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  • Calculations of Performance Losses for Automobile Vehicles
    210-218
    Views:
    207

    Vehicle-energetic-models are used to analyze the performances and when a comprehensive structure is established even optimization could be done. For these kinds of models, the losses of the vehicles have to be known. These losses could significantly effect of the vehicle fuel consumption. From these losses the rolling resistance, drive elements and aerodynamic drag are discussed. This paper reviews some of the literatures that describes the calculation methods and gives us some idea about the degree of their value. Our further goals are to have an UpToDate loss coefficient dataset and calculation methods for further vehicle-energetic modelling.

  • Parametric Programming Applied to the Optimal Production Structure in Determining
    375-389
    Views:
    114

    The agricultural planning often the question arises, how the different input (fertilizer, feed, irrigation, etc) from what to use on a production (land, animals) unit basis, and to what intensity. The input transformational efficiency experiments by setting analysis and evaluation. For example examined the nutrient replenishers fertilization experiments, the effect of nutritional values of the feed on the body weight gain, milk production in animal experiments. The input input efficiency to the external environment (weather, soil conditions, unexpected events), the technology used and the biological factors both influence. The farmer must be chosen in each sector, taking into account the magnitude of these inputs and environmental requirements. The economic optimum is usually trying to approach the sectoral level, which serves as the basis for future planning data. The mathematical programming models using relatively simply and quickly determine the optimal production structure. The models provide the specific resource requirements for, and the limitations of the objective function coefficients are calculated on the basis of sectoral. This becomes a deterministic model, and we can get the appropriate sectoral analyzes outstanding results of production structures. Therefore the relationships within sectors directly incorporate mathematical programming model and corporate interests placed above the interests of the industry to determine the intensity of the sectoral inputs. in their article a fertiliser application example, we present the production structure and the plant production sector fertiliser input of a time optimization, in which the fertilizer for specified sectoral relationships appear in the model objective function.

  • Role of Lean and Agile Supply Chain Models for Pellet Fuel Technologies
    119-130
    Views:
    148

    Business organisations constantly strive to improve their processes, both internal and external. Within the supply chain of a product, different strategies can be applied. This paper aims to answer the basic questions like what is the core of lean and agile SCM strategies, what are the differences of the two models, and how can they be combined. This paper examines further, which of these SCM models and what elements of them can be applied for wood pellet supply chains, also examining the possibility of their combination. The result of these examinations is, that even though fuel pellets can be considered as simple commodity and not a very innovative product, diversity in input characteristics, optimization of fuel pellet technology process variables and changes in output market qualities and quantities need sometimes agile, flexible answer from pellet fuel SCM. The basically lean character of pellet fuel technologies and SCM can further enhanced by implementing agile SCM model elements, as is the increased integration of suppliers into the supply chain.

  • Examination of Infrared Tomato Drying
    303-309
    Views:
    88

    Tomato is a highly perishable food, thus preservation is required to meet the continuous market demand compared to the unbalanced yearly production peak. The aim of this paper is to show a detailed insight into infraradiation based drying process. Furthermore, to widen the possible usage range of a well-known approximation method for describing the temporal moisture variation in function of process parameters. The mass decrease of tomato slices was examined, in function of specific radiation power, heat source and sample distance, in forced and natural airflow. Based on the results dimensionless moisture ratio change over time was fitted as an exponential function, which may be used in industrial drying process optimization.

  • Monitoring of Debrecen WWTP Biogas Fermentation Processes by Chemical Methods
    79-83
    Views:
    162

    The anaerobic digestion is a widely used economical method for sewage sludge stabilization and also purification of waste water with a high organic content. All effective anaerobic digesters transform the organic matter into biogas containing methane, which usable component covers a significant share of the heat and electricity consumption of the wastewater treatment plant (WWTP). The increasing amount of biogas is a priority task of WWTPs, which we can achieve a deeper knowledge of anaerobic digestion processes. The main task of this study is the optimization of anaerobic sludge treatment of Debrecen WWTP. Digester towers processes and their impact on the biogas yield were also priority studied.

  • Global Inversion of Pressure Dependent Acoustic Velocity Data Based on a New Rock Physical Model
    47-55
    Views:
    135

    In this paper with the further development of our previously published single exponential model, the new multiple exponential model describing the pressure dependence of acoustic longitudinal wave velocity is presented. Since with increasing pressure in the rock several relaxation mechanisms at the same time can cause the increasing propagation velocity, the new model can handle two or more physical mechanisms (e.g. the closure of pore volume or microcracks or friction on grain boundaries etc.). The previously applied linearized inversion procedure can trap in a local minimum, so during laboratory measured longitudinal velocity-pressure data processing a global optimization method was used to find the absolute minimum. Using the developed model equation as response equation in a Simulated Annealing algorithm the petrophysical parameters of the model can be determined. Inversion results proved that the calculated data using the new model and algorithm matched more accurate with measured data on a rock sample.

  • Construction Solutions for Reducing the Effect of the Rear-end Collision
    Views:
    140

    Analysing the accident statistics, we can detact that, the improvement of the transport safety is one of the most important engineering task. The number of the vehicles in the trasport gets significantly higher from year-to year, and the infrastructure of the cities frequently can not coordinate already it. Therefore the increasing of the vehicles’s number naturally involves the upgrowth of the accidents occasions too. The aim of the improvement of the vehicle-construction to reduce the personal injured and death resulted accidents number in contrast with the increasing traffic performance. This study analyses the construction options for reducing the effect of the rear-end collision whiches are concentrated for the passive vehicles and its passengers firtsly.  Among the actual car manufacturers applied solutions, foward-looking possibilities and suggestions are described in this publication. The development can not be concentrated for only the safety improvement, the mass-optimalization must be completed simultenously. These apparent contrary requirements can be completed with application of new materials. Therefore the study addresses the more optimal utilization of the meatl foam in the vehicles crushbox. In addition, an optimized break-assist solution is described based on the Mercedes developed Pre Safe Plus® system to increas the abrorbtion of the impact energy.

  • Optimization and Analysis of Structure about Lifting Device of Logistics Sorting
    425-431
    Views:
    158

    The lifting device of a logistics sorting machine needs high frequency upward and downward reciprocating motion therefore the cutting fork arms and matching parts of the shaft are often worn out. In this paper the problem of the shear fork types applied for the lifting mechanism is studied at first. Then the advanced numerical simulation software ANSYS adopted for the lifting mechanism of the shear fork type, and the means of virtual simulation is introduced. Hence the possible location of faults and fault modes are analysed. Then improving measures about the lifting mechanism of the logistics sorting machine are suggested.

  • Vehicle dynamics modelling of an electric driven race car
    106-114
    Views:
    121

    In the following we are presenting a vehicle dynamics simulation program developed in MATLAB environment. The program is capable of calculating the dynamics functions of a vehicle from its technical data. The program has been successfully applied for the optimization of the technical data of an electric driven race car that was designed and constructed at the Department of Mechanical Engineering of the University of Debrecen.

  • Analysis of Activity Times in the Process of a Wooden Box Manufacturing
    475-484
    Views:
    119

    The main target of companies is to earn money and achieve profit. In order to fulfil these needs, companies have to reduce their costs. Cost reduction is often associated with bad quality products, but it could be done in a different way. Sometimes it is enough to examine only their own processes and then benefit from the process optimization, process improvement or process scheduling. In this article a case study is presented, in which the differences in a production scheduling are evaluated with the application of Monte-Carlo simulation and descriptive statistics. At the end of the paper the most efficient material sequence is selected at the manufacturing company by using weighted sum model

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