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Found 6319 publications

The Forerunner UAV Concept for the Increased Safety of First Responders

No authors available

Publication Name: International Conference on Vehicle Technology and Intelligent Transport Systems, VEHITS - Proceedings

Publication Date: 2021-01-01

Volume: 2021-April

Issue:

Page Range: 362-369

Description:

This paper proposes a novel Forerunner UAV concept to increase the safety of first responders by monitoring the road in front of their emergency ground vehicle (EGV) and notifying the driver about any violation of his/her right of way or approaching danger. The developments are conducted in an R&D project in Hungary. The proposed UAV for the planned urban demonstration is a hexacopter with triple redundant architecture applying a gimbaled camera to monitor the surroundings. In the cooperative control of the EGV and UAV the UAV must fly in front of the EGV which is possible through wireless communication of route data and velocity. Besides the real system a computer simulation representation is also applied including CARLA and Matlab to make exhaustive tests of the system capabilities. Increased attention is devoted to the possible wireless communication solutions as these are safety critical parts of the system. The article ends with the lists of planned simulation and real test scenarios to evaluate the system.

Open Access: No

DOI: DOI not available

SCHEDULING OF WASTE WOOD PROCESSING FACILITIES WITH OVERLAPPING JOBS

No authors available

Publication Name: Proceedings of the 16th International Symposium on Operational Research in Slovenia, SOR 2021

Publication Date: 2021-01-01

Volume:

Issue:

Page Range: 321-326

Description:

An important phase in most waste wood value chains is the processing of bulk waste from various sources, usually by means of shredding. This paper presents a method for scheduling the machines in such a waste wood processing facility, where incoming deliveries of different types of wood are processed by a series of treatment and transformation steps to produce shredded wood. A mathematical model is presented for the problem, that allows overlaps between consecutive steps to optimize resource flow through the system. The efficiency of the model is presented on randomly generated instances.

Open Access: No

DOI: DOI not available

Privacy and Governmental Transparency

Miklós Könczöl András Lapsánszky Ákos Tussay András Koltay

Publication Name: Public Governance Administration and Finances Law Review

Publication Date: 2021-01-01

Volume: 6

Issue: 2

Page Range: 5-6

Description:

No description provided

Open Access: Yes

DOI: 10.53116/pgaflr.2021.2.1

Investigation of effect of water content on railway granular supplementary layers

Szabolcs Fischer

Publication Name: Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu

Publication Date: 2021-01-01

Volume: 2021

Issue: 3

Page Range: 64-68

Description:

Purpose. To determine the relationship between water content of continuously graded granular supplementary layers for railway substructure and their inner shear resistance and load bearing capacity. Methodology. Four different ‘samples’ were produced as standard granular products from andesite. Two of them are common base courses for road construction in Hungary, the other two are common railway supplementary layers. The author performed laboratory measurements (multilevel shear box tests) that are adequate for the evaluation of inner shear resistance. The measurements of load bearing capacity and Proctor tests were executed in the laboratory of Colas Hungaria Ltd. The author performed measurements with the optimal water content values of each sample, as well as lower and higher values than them. This can show how the given granular material is sensible to the change of water content. Findings. It was proved that the granular supplementary layers, which are standardized products in road construction (as base courses), also seems to be adequate in railway construction; they are not so sensible to the variation of their water content. It does not mean that the other two granular layers are not adequate for railway substructures, but the application of road ‘products’ have to be considered as substitute products. Originality. The author tried to emphasize the adequacy of rock mining for construction of ballasted railway tracks, as well as the optimal use of mineral wealth in every country with its results. Practical value. The obtained results of the present paper can be useful in the area of rock mining, and railway infrastructure engineering. During construction procedures the optimal water content values should be taken into considerations for compaction to be able to reach maximal compactness (density), but too high water content has to be avoided, which is based on the results. They can be also considered in the design phase.

Open Access: Yes

DOI: 10.33271/nvngu/2021-3/064

Investigation of the shelf life of fruit yogurts as a function of the treatment of flavoring substances

E. Lakatos V. Kapcsándi

Publication Name: Elelmiszervizsgalati Kozlemenyek

Publication Date: 2021-01-01

Volume: 67

Issue: 1

Page Range: 3293-3314

Description:

1. SUMMARY Milk and dairy products represent one of the foundations of the human diet because of their valuable ingredients and pleasant sensory properties. The aim of our research was to investigate how different heat treatment processes (microwave irradiation, drying) affect the shelf life of dairy products (yogurt) from a microbiological point of view. In the course of our measurements, the effects of the different heat treatment parameters of the flavoring substances used in the production of the products (apples, bananas) on the microbiological properties of the products and, thus, on their shelf life were investigated. In our experiments, conventional drying (55 °C, 24 hours) and microwave irradiation technology (800 W, 55 °C, 10 min) were used as treatment forms of the additives. Comparisons were made in terms of microbiological parameters (total viable count, yeast/mold count and E. coli/coliform count). Based on our results, we believe that the drying process can ensure microbiological safety in food production if the air circulating in the equipment has adequate hygienic properties. The microwave irradiation technology can be used successfully to inhibit microbes in foods, in this case fruits. However, the same treatment parameters cannot be applied to different fruits.

Open Access: Yes

DOI: 10.52091/JFI-2021/1-3-ENG

Processing systems design considering resilience

Ákos Orosz Jean Pimentel Ferenc Friedler

Publication Name: Computer Aided Chemical Engineering

Publication Date: 2021-01-01

Volume: 50

Issue: Unknown

Page Range: 807-812

Description:

The resilience of a system is defined as the system's capability of recovering from failures. Traditionally, only predictable aspects are considered when designing processing systems. Evaluation of these aspects is performed via assessment of exact indicators and enumeration of all cause-effect options. However, such evaluation is not appropriate for determining the resilience of processing systems, since resilience is based on unexpected events in addition to the expected ones. Consequently, the cause part of the cause-effect relation is not known or not effective. In the current work, the general formula for determining resilience of a system is embedded into a P-graph based process synthesis algorithm. Thus, the resilience can be considered when selecting the most preferred process during its synthesis. The result is illustrated by synthesizing a process of adipic acid production by nitric acid oxidation of KA oil.

Open Access: Yes

DOI: 10.1016/B978-0-323-88506-5.50126-1

Sight distances at unsignalized intersections: A comparison of guidelines and requirements for human drivers and autonomous vehicles

Mariusz Kieć Csaba Koren Attila Borsos Zsófia Magyari

Publication Name: Archives of Transport

Publication Date: 2021-01-01

Volume: 59

Issue: 3

Page Range: 7-19

Description:

Many traffic accidents are caused by unforeseen and unexpected events in a site that was hidden from the driver's eyes. Road design parameters determining required visibility are based on relationships formulated decades ago. It is worth reviewing them from time to time in the light of technological developments. In this paper, sight distances for stopping and crossing situations are studied in relation to the assumed visual abilities of autonomous vehicles. Current sight distance requirements at unsignalized intersections are based among others on speeds on the major road and on accepted gaps by human drivers entering or crossing from the minor road. Since these requirements vary from country to country, regulations and sight terms of a few selected countries are compared in this study. From the comparison it is remarkable that although the two concepts, i.e. gap acceptance on the minor road and stopping on the major road have different backgrounds, but their outcome in terms of required sight distances are similar. Both distances are depending on speed on the major road: gap sight distances show a linear, while stopping sight distances a parabolic function. In general, European SSD values are quite similar to each other. However, the US and Australian guidelines based on gap acceptance criteria recommend higher sight distances. Human capabilities and limitations are considered in sight field requirements. Autonomous vehicles survey their environment with sensors which are different from the human vision in terms of identifying objects, estimating distances or speeds of other vehicles. This paper compares current sight field requirements based on conventional vehicles and those required for autonomous vehicles. Visibility requirements were defined by three vision indicators: distance, angle of view and resolution abilities of autonomous cars and human drivers. These indicators were calculated separately for autonomous vehicles and human drivers for various speeds on the main road and for intersections with 90° and 60° angles. It was shown that the required sight distances are 10 to 40 meters shorter for autonomous vehicles than for conventional ones.

Open Access: Yes

DOI: 10.5604/01.3001.0014.9553

Hungarian experiences of the transition from traditional work to telework1

No authors available

Publication Name: Transformations in Business and Economics

Publication Date: 2021-01-01

Volume: 20

Issue: 3

Page Range: 168-182

Description:

The global outbreak of the COVID-19 epidemic has radically transformed people’s daily lives since the spring of 2020. In addition to the direct health consequences of the virus, the epidemic has had a significant impact on the functioning of society, people’s lifestyles and has also had a fundamental impact on the world of work. The year 2020 marked a breakthrough in the spread of telework and “home office” work in Hungary, as this form of work was one of the necessary tools in the fight against the COVID-19 epidemic in order to reduce the number of personal contacts. Both employers and the masses of employees were able to experience the pros and cons of this. This period can be therefore considered as the main challenge of teleworking and working from home, which is undoubtedly caused by the COVID-19 epidemic. The research aims to answer the question of the impact of telework on the daily lives of Hungarian workers. In international comparison, the proportion of teleworkers in Hungary was low before the pandemic. As a result, a great many have experienced a drastic transition from traditional work to teleworking. The given questionnaire survey also confirmed that a significant proportion of employees had difficulties with teleworking at the beginning of the transition. These difficulties were mainly due to the fact that they were not technically prepared and that their daily routine, which they had become accustomed to in their traditional work, had been changed.

Open Access: No

DOI: DOI not available

Determination of center of gravity and moment of inertia using dynamic testing method

No authors available

Publication Name: "Advances in Acoustics, Noise and Vibration - 2021" Proceedings of the 27th International Congress on Sound and Vibration, ICSV 2021

Publication Date: 2021-01-01

Volume:

Issue:

Page Range: Unknown

Description:

The knowledge of a vehicle's center of gravity (COG) and moment of inertia (MOI) are important from vehicle dynamic and comfort points of view. These parameters can be determined from the CAD model of the vehicle, however, manufacturing inaccuracies and additional elements can modify the values, and experimental validation can be necessary. The determination of COG (and even MOI) can be carried out using classical physical methods, but a more convenient and sophisticated method is offered based on dynamic testing data. The method is known and accessible even in commercial testing software, but a clear recommendation for the optimal input data and the expected accuracy is still not available. The purpose of this study is to define the influencing factors of the measurement and quantify their effect. The introduced method is based on the evaluation of the frequency response functions in the mass-line region. Input data were obtained by using impulse hammer excitation and accelerometers for measuring the response of the structure. The measurements and the evaluations were performed in Siemens LMS Test.Lab software using Rigid Body Calculator module. The results of the dynamic measurement are compared to CAD data and to the COG value got from simple static measurement.

Open Access: No

DOI: DOI not available