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An Analysis of Rotational Line Mating Using Computer Simulation
Published December 6, 2005
35-39

In a simulation examination, we analyzed the effect of the family size and the rate of pairing on the survival of rare genes, to keep the level of variation of the genepool and to avoid the loss of alleles.
The population size was 360 animals. In the simulation, we calculated on the basis of a discrete population. We placed the 360 animals i...nto different clusters, with 3 types of frequencies of alleles and 3 types of groups. We assumed 2, 3 or 4 alleles in 8 loci. We generated 15 generations using the same mating and selection system used in practise. The simulation was written with Scilab 2.7.2 software, and evaluated with SPSS software.
There were significant changes in the effect of family size on the genetic variation in the following cases: when the base population had the same gene frequencies in all loci, and when the gene frequencies were between 0.125-0.75. In these cases, we found that the smaller families (10 animals/cluster) were better than the larger families (30 or 90 animals/cluster). The first generation where there accured a loss of alleles was averagely earliest in larger families (90 animal/cluster). This average was 3.37 generations. When we are searched the effects of the different rates of pairing we found those cases most favourable when the ratio of males and females was 1:2 or 1:4 as compared to 1:9. The first generation where there was a loss of alleles was averagely earliest at the ratio of pairing male and females of 1:9 (the mean was 3.05 generations) when the frequency of the rarest allele was 0.0069.
The recently introduced rotating-random mating system is an eligible method for small populations for the preservation of genes.

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Biomass production estimation of processing tomato using AquaCrop under different irrigation treatments
Published December 15, 2019
131-136

The wiser usage of irrigation water is inevitable in the future. Irrigation has very high input cost; therefore, farmers must carry out irrigation with care. Also, the effect of irrigation on crops has a big role in decision making. Modeling provides a possibility to evaluate this effect. AquaCrop, as a crop production simulation model has grea...t potential in this field. The accuracy of tomato biomass yield prediction of the model was tested in this research. For collecting the necessary data, a field experiment was conducted at Szarvas on processing tomato with different water supplies, such as 100% (I100), 75% (I75), 50% (I50) of potential evapotranspiration and a control with basic water supply (C). The relation of the simulation and actual biomass yields was evaluated during the season. Very good correlation was found between the modelled and the actually harvested data. The data for the control and I100 treatments showed higher correlation than the I75 and I50. The relationship for all of the data was moderately strong. Miscalculations occur mostly when the dry biomass yield reaches
7 t ha-1. The accuracy of the model was evaluated with the use of mean absolute error (MAE) and root mean squared error (RMSE) values. The least error was found in the C treatment, which means 0.34 MAE and 0.45 t ha-1 RMSE. The simulation resulted in higher errors in the I75 and I50 treatments.

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Managing risk using real options in company’s valuation
Published April 8, 2014
125-132

The valuation of company is very important because provides information about the current value/situation of company, and through this, provide the opportunity of choosing the best company’s growth alternatives. The future strategic decisions are characterized by lack of knowledge, information, so all measures of company’s growth are closel...y linked with uncertainty and risk. The company’s valuation process is also related with uncertainty and risk. The risk may result both from the assessed assets and the technique used. In literature, we could find three approaches for risk management: capital budgeting based method, methods based on portfolio analysis and real options approach of risk management. Among them, the real options based methods is the most revolutionary approach for risk management. The advantages of the method, consists in the fact, that the process of establishing strategic decisions integrates the possibility of reversibility, delay and rejections, which isn’t it possible at two previous methods. The method also takes into account the total risk of company, so both the company-specific and systematic risk. In this study, I have used one of the best-known real option based method, the Black-Scholes model, for determining the option’s value. Determination of option value is based on the data of enterprise, which was tested Monte Carlo simulation. One of the basic assumptions of the Black-Scholes model is that the value of option is influenced by several factors. The sensitivity of option’s value could be carried out with so-called “Greeks”.. In the study the sensitivity analysis, was carried out with indicators Delta (Δ), Gamma (Γ) and Vega (ν). The real options based risk management determinations were performed in the R-statistics software system, and the used modules are 'fPortofio' and 'mc2d'. By using of real options method, I have calculated the average value of company capital equal with 38.79 million. By using simulation was carried out 1000 runs. The results of this show a relatively low standard deviation, small interquartile range and normal distribution. In the calculation of indicator Delta, could be concluded the value of company moves in 0.831 proportion to the price of options, the standard deviations of index is low, so the real option based method could be used with success in company’s value estimation. The Gamma index shows the enterprise value is sensitive just for large changes. The result of Vega reflects the value of option, so the company’s value volatility, which is small in this case, but this means a volatility of value. In summary, we can conclude that the call options pricing model, well suited for the determination of company’s value.

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Simulation of optimizing decisions and risk analysis in investment plans
Published November 15, 2007
160-164

Investments always contain risks, as data referring to the future are planned and uncertain. Therefore, besides feasibility analyses we need to perform risk analyses, as well. Through statistic simulation methods, our aim is to examine how uncertain and prospective data as risk factors affect investment-profitability indices. On the other hand,... our aim is to find out the optimal innovation – financing decisions by using decision optimizing
methods.

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Production and economic risk analysis of pig fattening
Published April 8, 2014
171-176

I prepared a “model farm” producing fattening pigs in order to examine the main risk of production and market factors affecting the profitability of fattening pig production. Values of body weight (at the beginning of fattening and at the end of fattening), mortality rate, feed conversion ratio (FCR) of fattening pig as well as the main cos...t and price data were recorded as the input data of the model. Production value per unit, production cost per unit and income per unit were used as output. The Monte-Carlo simulation was used in the model for risk assessment. Based on the results of the analysis, it was concluded that the production value per unit was most affected by the selling price of fattening pig (ß=0.972), the production cost per unit were most influenced by the body weight at the beginning of fattening (ß=0.567) and the feed conversion ratio (ß=0.537), in addition, the change of the income per unit was most determined by the previously factors.

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The influence of channel network silting up at Žitný Ostrov to range of interaction between surface and groundwater
Published May 20, 2020
23-31

The movement of water resources, especially the possibilities of their regulation by interaction between surface and groundwaters are the subject matter of attention particularly during the occurrence of extreme hydrologic situation. This work presents the overview of knowledge and results which were achieved at IH SAS in this question. It ...can show the ways how to optimize the adjudicated processes which emerge during the requirement of emergency intervention. The solution of this task was located at the Žitný Ostrov area because this territory with their existence of channel network is suitable for studying the surface and groundwater interaction. The channel network at Žitný Ostrov was built up for drainage and also to safeguard irrigation water. The water level in the whole channel network system has an effect on groundwater level on the Žitný Ostrov and vice versa. It was been necessary to judge the impact of the channel network silting up by bed silts on the interaction between channel network and groundwater on the Žitný Ostrov. The aim was to evaluate the changes of bed silt state of Žitný Ostrov channel network and consecutively their influence on interaction processes between groundwater and surface water along the channels in the period from 1993 to present. The measurements of bed silt thickness in Žitný ostrov channel network had been started from1993, later they continued at selected profiles of three main channels – channel Gabčíkovo-Topoľníky, Chotárny channel and Komárňanský channel (for checking of the silting up variability). From 2008 the detailed field measurements of cross-section profiles aggradations along these selected three channels have been started. The objective of detailed field measurements was the determination of the silt permeability which is expressed by parameter of saturated hydraulic conductivity. This parameter was determined by two ways – as the saturated hydraulic conductivity obtained from disturbed samples of silt Kp and as the saturated hydraulic conductivity obtained from undisturbed samples of silt Kn. In the first case the granularity of silts was determined as a first step and then was computed their Kp from the empirical formulas according Bayer-Schweiger and Spacek. From undisturbed samples of silts which were extracted along the channels from top, middle and bottom layer of silts, were determined the values Kn by the laboratory falling head method. The valid values Kp on channel Gabčíkovo-Topoľníky ranged from
4,33 10-7 to 4,46.10-5 m s-1, on Chotárny channel from 5.98 10-5 to 2.14 10-6 m s-1 and on Komárňanský channel fluctuated from 1.93 10-6 – 6.09 10-5 m s-1. The valid values Kn on on channel Gabčíkovo-Topoľníky ranged from 5.21 10-8 – 4.18 10-3 m s-1 , on Chotárny channel ranged from 8.54 10-8 – 2.70 10-4 m s-1 and on Komárňanský channel fluctuated from 4.72 10-7 – 1.26 10-5 m s-1. The remarkable results were noticed by comparison of values of saturated hydraulic conductivity from disturbed and undisturbed samples Kp and Kn. On Chotárny channel the values of silt saturated hydraulic conductivity from undisturbed samples Kn approximately hundredfold decreased (from 10-6 to 10-8 m s-1). On Komárňanský channel the comparison of values Kp and Kn shown that the values Kn from undisturbed samples approximately tenfold descended against Kp.

Simultaneously, the bed silts‘ impact on the groundwater recharge (saturated hydraulic conductivity of silt) was also examined. Determination of the total recharge amount was done by numerical simulation (model SKOKY) and by the so-called method of interaction formulas. These two approaches were applied at the Žitný Ostrov channel network. There were field measurements performed in monitored three main channels and adjacent to obtain correct input data. These characteristics were used for simulation and computation of total recharge along the channels. The total recharge amount was calculated for four alternatives of the surface water levels in the channel and the surroundings groundwater respectively. We chose four simplified variants with the same geological conditions in surroundings area of channels, only water levels of groundwater and in channels were modified. The results of the simulations seem to show greater impact of the silt in the case of outflow from the channels to the surroundings than the inflow into the channel from the surroundings.

 

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The possibilities of biomass utilization in the field of spatial development
Published July 16, 2007
59-63

By joining the European Union, Hungary made a commitment to increasingly utilize renewable energy sources. Keeping in view the agricultural circumstances of Hungary, we can state that biomass utilization has, overall, the greatest range of possibilities to use its products as ‘energy sources’. Biomass raw materials are useful in meeting emi...ssion control regulations for environment protection and to reduce climate change. The role of biomass production in spatial and rural development and in rural employment, and also in the decrease of Hungary’s energy dependence, supports development in biomass energy use. My aim in studying biomass utilization is the creation of a micro-regional level, decentralised, agro-energetic system-model for the use of plant and animal biomass for energy purposes, whether naturally or by anthropogenic activity, on agro- and sylvicultural areas, and on animal breeding farms. This model simulation method serves as a planning base for policy-makers during the spatial planning processes. The examination is presently in the stage of data collection. The collection of the basic data of the examination area and the purchase of the necessary equipment, materials and maps has already started. Contact has been made with local stakeholders, municipalities, municipality associations and micro-region managers.

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Simulation Experiments for Observation of Different Genetic Parameters
Published May 11, 2003
46-49

The change of genetics variance in various simulated population were examined trough 25 generations. The population size were 1000, 2000, 4000, 8000 and 16000. The number of genes were1, 2, 3, 4 and 5. Two allels per gene were applied. It was assumed that base population was randomly mated. Also it was assumed that a pair of allel genes was ind...ependent, there was no epistasis, linkage between alleles of different loci, dominance and overlapping generations. In the selection was kept the 93% of females and 0.186% of males. The size of populations was close to constant through generations.
The size of populations and the number of loci were effects that how many generation is necessary to get genetical maximum. The change of the genetical mean of the population and the genetical variance were well subscribed cube and logistical curve. We can use to estimate these genetical parameters with the previous functons.

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Study of a Turkey Population for Gene Preservation
Published May 4, 2004
48-52

Genetic variability is very important in small populations. We examined an indigenous bronze turkey population which is bred for gene conservation in order to see if the current mating system maintains genetic variability. The present generation was surveyed using microsatellite markers and a computer model was used to simulate changes in the p...opulation over 100 generations.
The data was analysed using the concept of entrophy from information theory instead of genetic variance so that we could more accurately measure genetic variability.
The results indicate that the breeding method currently in use, rotational line mating, is acceptable with respect to preserving genetic variability, but new selection methods may provide additional protection against the loss of alleles.

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Computer simulation modeling of Leaf Area Index (LAI) in maize
Published February 25, 2014
5-8

This study presents a PHP-based model capable of calculating maize leaf area index. The model calculates LAI from emergence to 75% silking. The basis of calculation is represented by the daily average temperature values. The usability of the model was tested using three years' temperature and LAI data series from the values obtained by the weat...her station set up at the Látókép Experiment Site of the University of Debrecen, Centre for Agricultural Sciences between 1994 and 1996. During the running of the model, it was observed that temperature affects the intensity of leaf development to a various extent.

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The economicalness of apple production in view of post harvest technology
Published February 17, 2015
125-131

This study analyses how the level of postharvest technology’s development influences the economic efficiency of apple production with the help of a deterministic simulation model based on primary data gathering in producer undertakings. To accomplish our objectives and to support our hypotheses three processing plant types are included in the... model: firstly apple production with no postharvest and prompt sale after the harvest, secondly parallel production and storage combined with an extended selling period and thirdly production and entire postharvest infrastructure (storage, sorting-ranking, packing) with the highest level of goods production and continuous sales. Based on our results it can be stated that the parallel production (plantation) and cold storage, so the second case is proved to be totally inefficient, considering that the establishment of a cold storage carries enormously high costs with resulting a relative low plus profit compared to the first type of processing plant. The reason for this is that this type is selling bulk goods without sorting-grading or packaging; storage itself – as a means of continuously servicing the market - is not covered properly by the consumers. Absolute efficiency ranking cannot be established regarding the other two processing plants: plantation without post-harvest infrastructure resulting lower NPV, but a higher IRR, DPP and PI as developing a plantation and a whole post-harvest infrastructure. Former processing plant type is favourable considering efficiency ratios describing capital adequacy, while the latter is in terms of income generating capacity.

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Spatially Continuous GIS Analysis of Sampling Points Based on Yield and Quality Analysis of Sugar Beet (Beta vulgaris L.)
Published March 4, 2005
56-61

The homogeneity of a study area of 20x20 m used for beetroot production in North-West Hungary was analysed with geo-statistical methods on the basis of measured plant and soil parameters. Based on variogram calculations (Equation 1 and 2), the yield surface showed homogeneity in North-South direction. Considering the results, decrease of sampli...ng distance to 17 m can be suggested. The direction of the variability of yield (Figure 1) could be modelled with a direction variogram based on analysis of the variogram surface. In the study, developed methodological processes are presented for the analysis of spatial relationship between measured production and soil parameters. 5 spatial evaluation methods for yield surface were compared (Table 1). On the basis of the analysed methods, it can be stated that different methods (LP, RBF) should be used when the reasons for locally extreme yields are in focus than in case when the yield surface of the whole area is estimated (IDW, GP). Using adequate parameters the kriging method is applicable for both functions. Similarly to the results of an ordinary Pearson correlation analysis, spatial correlation analysis was shown using soil pH and Cu concentration data. The results of cross variogram analysis (Equation 2) and the North-South direction of the variogram surface showed negative correlation (Figure 3). Based on simulation calculations, decrease of 30% in sampling points resulted in increase of 12% in error for the total sample number considering Cu concentration. The method provides a tool to decrease the cost of sampling and sample analyses of spatially correlating features, and to increase the reliability of spatial estimation using a better sampling strategy with the same sample number.

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Economicalness of self-propelled work platforms in superintensive apple plantations
Published February 18, 2016
91-98

The main goal of this study was to determine whether the use of work platforms in super intensive apple orchards in order to reduce production costs and enhance work area performance under Hungarian circumstances an economic investment is. The analysis was carried out using a deterministic simulation model based on primary data collection from ...apple producing businesses. The results show that work platforms have remarkable economic advantage in case of operations with high machine work expenditures or where they significantly improve the area performance of manual labour. The former was due to the much lower operating costs of work platforms compared to tractors, while the latter comes clear from reduction of manual labour input per hectare. The greatest economic advantage of work platforms occurs in case of harvesting and pruning, but in case of other operations they have no significant cost advantage. They main economic disadvantage is, however, that apple breaks more when harvesting with work platforms, i.e. picking quality deteriorates significantly. It can be concluded, that purchase of work platforms cannot be considered economic investment under Hungarian circumstances. It might be economic, utilised on maximum area (ca. 30 hectares) by certain companies in special cases, but in most cases has no favourable payback conditions.

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Economics of hail protection net installation in super intensive apple orchards
Published February 18, 2016
27-35

The main objective of this study was to determine and organize beneficial and detrimental effects of hail protection nets, and as far as possible to quantify their economic impact. The main factors were determined, through which hail protection nets can affect the costs and incomes of the production, and as their sum the economic result. Consid...ering these factors together with the investment cost and the annual maintenance costs allows the economic evaluation of purchasing of hail protection nets. The analysis was carried out using a deterministic simulation model based on primary data collection from apple producing businesses. Installing hail protection nets as additional technological elements of intensive apple orchards can be concluded by all means as an economic investment – trough their protective effect. However, to achieve really favourable economic indicators, definitely bigger tree height is needed making possible the realisation of around 8.0 t ha-1 extra yield. The main root of this phenomena are obviously the extremely high investment costs of hail protection nets, which result in a large mass of fixed costs during the production period. Therefore the basic economic interest is reaching higher yields and thereby higher profits per unit area.

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