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Found 6289 publications

Averaged vibration levels during courier parcel delivery service in small truck in Hungary

Péter Böröcz

Publication Name: Fme Transactions

Publication Date: 2018-01-01

Volume: 46

Issue: 2

Page Range: 211-217

Description:

In recent years there continues to be an increase in courier parcel delivery services due to the growing global online economy and express parcel shipments. It is therefore important to measure and quantify the levels of vibration that occur inside the vehicle during transport, as it can be one of the primary sources of damages. The purpose of this study was to measure the averaged vibration levels in vertical, lateral and longitudinal directions that occur in courier delivery shipments from pickup to delivery involving small trucks over ground road transportation in Hungary. The recorded acceleration data were analyzed in terms of power spectral densities (PSD) and presented with overall Grms. The results of the separated afnd averaged vibration levels provide physical circumstances for various road and load conditions showing those frequency bands that have significant intensities.

Open Access: Yes

DOI: 10.5937/fmet1802211B

Development of a 400V/1000A inverter for testing electric drivetrains

Zoltán Szeli Gábor Szakállas

Publication Name: 31st International Electric Vehicle Symposium and Exhibition Evs 2018 and International Electric Vehicle Technology Conference 2018 Evtec 2018

Publication Date: 2018-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

The article describes the development process of an inverter that is suitable for driving, testing and supporting the development of synchronous and asynchronous electric motors. Design concepts and goals, hardware architecture, system components, built-in features and protections are presented regarding the power stage.

Open Access: Yes

DOI: DOI not available

Towards a modern, integrated virtual laboratory system

Miklós Kuczmann Tamás Budai

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2018-01-01

Volume: 15

Issue: 3

Page Range: 191-204

Description:

The aim of this paper is to give an overview on virtual and remote laboratory systems and to evaluate current solutions focusing on feasibility and applicability in higher education. Based on the conclusions of this evaluation, a new set of requirements are established against a modern virtual laboratory system. Finally, an overview of state of the art infocommunication technologies, including cognitive infocommunication are presented, which can help create high user experience in the new virtual laboratory environment.

Open Access: Yes

DOI: 10.12700/APH.15.3.2018.3.11

Comparison between European protestant and catholic economic development through modern painting

Bernadett Balassa

Publication Name: Deturope

Publication Date: 2018-01-01

Volume: 10

Issue: 1

Page Range: 82-96

Description:

Since Max Weber, economists suggest that religious activity affects the European economic development, and this hypothesis was proven between the seventeenth and nineteenth centuries. Accordingly Protestant economic thinking accelerated the evolving system of capitalism, giving adequate attitudes to the accumulation of wealth. This research supposes that the mentioned capitalist approaches have their own impressions on visual arts, particularly on modern painting. It examines almost nine hundred religious paintings from the fifteenth to nineteenth centuries, investigating signs of business activities on the artworks. This form of qualitative examination apply the methodology of content analysis. As a result of the study the former hypothesis of Weber could be verified from multidisciplinary approach.

Open Access: Yes

DOI: 10.32725/det.2018.005

Batch process scheduling with eS-graph: A case study

Máté Hegyháti

Publication Name: Chemical Engineering Transactions

Publication Date: 2018-01-01

Volume: 70

Issue: Unknown

Page Range: 115-120

Description:

The scheduling of batch processes is a widely researched field of chemical engineering. Over the last few decades, a great number of tools have been developed for industrial examples and literature problems. These methods vary not only in their applied model, but in their representation of the problem inputs as well. The most well-known representations are the State-Task Network, the Resource-Task Network, the State Sequence Network, and the S-graph. While the latter also serves as the mathematical model for the related optimization approaches, the others only act as an intermediate model between the raw problem data and the model used for optimization, e.g., a mixed-integer linear programming model. The eS-graph model is a generalization of the S-graph, where the one-to-one relation between nodes and tasks has been relaxed, allowing a much wider range of scheduling problems to be tackled. Processes may simultaneously occupy several units, and release them at different stages of execution, and certain stages of separate processes can be forced to overlap in time. As in the case of the S-graph, the eS-graph models can be solved to optimality by specially designed combinatorial algorithms or serve as a basis for precedence based linear programming formulations. In this work, the modelling capacities of the eS-graph framework are illustrated via a Polymer production case study, where complex timing constraints are present.

Open Access: Yes

DOI: 10.3303/CET1870020

Robot coverage path planning based on Iterative Structured Orientation

Claudiu Radu Pozna Radu Emil Precup Ernö Horváth

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2018-01-01

Volume: 15

Issue: 2

Page Range: 231-249

Description:

Coverage path planning for mobile robots aims to compute the shortest path that ensures the overlap of a given area, with applications in various domains. This paper proposes a coverage path planning strategy, referred to as Iterative Structured Orientation Coverage, which has two main advantages over the state-of-the-art, namely it is it versatile and it is capable to handle complex environments. The path planning strategy is expressed as three new approaches to coverage path planning. The suggested approaches are validated by simulation and experimental results. The source codes along with the test set are available in a public repository.

Open Access: Yes

DOI: 10.12700/APH.15.1.2018.2.12

Shift in the annual growth cycle of grapevines (Vitis vinifera L.) in West Hungary

K. Kozma A. Pozsgai E. Kovács J. Puskás

Publication Name: Applied Ecology and Environmental Research

Publication Date: 2018-01-01

Volume: 16

Issue: 2

Page Range: 2029-2042

Description:

Regional climate change has noticeable influence on grape and wine production in West Hungary. Sopron and Zala wine-growing regions are among the potential winners of the climate change, previously rather unsuitable for viticulture. Over the past 30 years, the minimum and maximum temperatures significantly increased, the precipitation decreased, nevertheless, the convective precipitation increased by 14 days during the growing season. Each climate indicator has changed between 1986 and 2015 compared to the previous 30 years (1956-1985). One of the effects of climate change is a significant shift in the annual growth cycle of grapevines (phenological phases). Budbreak begins nearly 8 days earlier, flowering 7 days and the veraison 8 days, while the harvest has been shifted to a date 11 days respect to the previous period. The time between the budbreak and the flowering has shortened by 4.5 days.

Open Access: Yes

DOI: 10.15666/aeer/1602_20292042

A survey of the applications of fuzzy methods in recommender systems

Peter Foldesi A. Tormási Brigita Sziová L. T. Kóczy

Publication Name: Studies in Fuzziness and Soft Computing

Publication Date: 2018-01-01

Volume: 361

Issue: Unknown

Page Range: 483-495

Description:

In the past half century of fuzzy systems they were used to solve a wide range of complex problems, and the field of recommendation is no exception. The mathematical properties and the ability to efficiently process uncertain data enable fuzzy systems to face the common challenges in recommender systems. The main contribution of this paper is to give a comprehensive literature overview of various fuzzy based approaches to the solving of common problems and tasks in recommendation systems. As a conclusion possible new areas of research are discussed.

Open Access: Yes

DOI: 10.1007/978-3-319-75408-6_37

Unsupervised clustering for deep learning: A tutorial survey

Peter Galambos Artúr István Károly Robert Fuller

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2018-01-01

Volume: 15

Issue: 8

Page Range: 29-53

Description:

Unsupervised learning methods play an essential role in many deep learning approaches because the training of complex models with several parameters is an extremely data-hungry process. The execution of such a training process in a fully supervised manner requires numerous labeled examples. Since the labeling of the training samples is very time-consuming, learning approaches that require less or no labeled examples are sought. Unsupervised learning can be used to extract meaningful information on the structure and hierarchies in the data, relying only on the data samples without any ground truth provided. The extracted knowledge representation can be used as a basis for a deep model that requires less labeled examples, as it already has a good understanding of the hidden nature of the data and should be only fine-tuned for the specific task. The trend for deep learning applications most likely leads to substituting as much portion of supervised learning methods with unsupervised learning as possible. Regarding this consideration, our survey aims to give a brief description of the unsupervised clustering methods that can be leveraged in case of deep learning applications.

Open Access: Yes

DOI: 10.12700/APH.15.8.2018.8.2