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Found 6289 publications

Hierarchical robust control for in-wheel motor vehicles

No authors available

Publication Name: Proceedings of the Mini Conference on Vehicle System Dynamics, Identification and Anomalies

Publication Date: 2014-01-01

Volume: 2014-January

Issue:

Page Range: 71-81

Description:

The paper proposes the design of an integrated vehicle control system for in-wheel electric vehicle, which is able to track road geometry with a predefined reference velocity. In the design the lateral and longitudinal dynamics are combined using the in-wheel motors and the steering system. The design methodology of the hierarchical control is proposed. The required control signals are calculated by applying high-level controllers, which are designed using a robust control method. For the control design the model is augmented with weighting functions specified by the performance demands. The actuators generating the necessary control signals in order to achieve the requirements for which low-level tracking controllers are designed.

Open Access: No

DOI: DOI not available

Sensitivity and validity of the fuzzy signature based evaluation of residential building conditions

No authors available

Publication Name: Civil-Comp Proceedings

Publication Date: 2014-01-01

Volume: 105

Issue:

Page Range: Unknown

Description:

The characteristics and the status of the existing stock of residential buildings are extremely important for the national economy of all countries including Hungary. Formerly some methods and approaches to formally tackle and evaluate individual buildings based on available records and expert reports were formulated. These methods are suitable for the evaluation and ranking of residential buildings and make it easier to complete the status assessment and decision support for further utilization. A mathematical analysis has been conducted to identify the sensitivity of the calculated final results in the case of the applied fuzzy signatures related to the changes of the membership values at the leaves (the end nodes of a graph). This paper briefly presents the methods, then it investigates the validity of these results taking into consideration the possible subjective discrepancy and certainty in the evaluations.

Open Access: No

DOI: DOI not available

Integrated robust control design for in-wheel-motor vehicles

Timea Fülep Zoltán Szabó Peter Gaspar Mihály András Ferenc Szauter József Bokor

Publication Name: Fisita 2014 World Automotive Congress Proceedings

Publication Date: 2014-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

The paper proposes a multi-layer supervisory architecture for integrated control systems in road vehicles. The role of the supervisor is to coordinate active control components and provide priority among them. The supervisor has information about the current operational mode of the vehicle and it is able to make decisions about the necessary interventions into the vehicle components and guarantee the reconfigurable operation of the vehicle. The decisions of the supervisor are propagated to the lower layers through predefined interfaces encoded as suitable scheduling signals. The contribution of the paper is the application of the LPV methodology in a design case study in which an integrated control of four wheel independently-actuated electric vehicle with active steering system is developed.

Open Access: Yes

DOI: DOI not available

Beer game - Demonstration and performance evaluation of supply chains

Diána Strommer Norina Szander Péter Bajor

Publication Name: Proceedings of the European Conference on Games Based Learning

Publication Date: 2014-01-01

Volume: 2

Issue: Unknown

Page Range: 732-741

Description:

Professionals need special skills in supply chain management to perform all the required tasks - organising material and information flow, product development, forecasting, customer services and relations, warehousing, decision making and performance measurement. The scientific literature and empirical studies show consistently that in addition to this complex frame of operations the bullwhip effect is presence in every case. This expensive phenomena is hard to detect and measure, and able to cause serious problems in the chains. We consider the game based learning is an effective way to gain experiences rather than acquire only the theoretical background. The beer game as supply chain simulation is widely accepted in the demonstration of system dynamics and investigations of bullwhip effect. Considering the advantages and drawbacks of the numerous versions of the game we created android software for the trainings. The paper based training is hard to follow, in the boardgame the participants can't satisfy the basic rule of not sharing any information and the online version won't make the common/group learning possible. Our training use the beer game simulation connected with the Balanced Scorecard measurement system helps the participants to develop skills in recognition of the bullwhip effect, being familiar with the triggers and impacts, have tools for mitigation and the skill of choosing or designing solutions in the specific cases. The participants can study the theories, evaluate several inventory and order strategies and they also get instant feedback on the impact of their decisions.

Open Access: Yes

DOI: DOI not available

Predicting flight arrival times with a multistage model

Gabor Takacs

Publication Name: Proceedings 2014 IEEE International Conference on Big Data IEEE Big Data 2014

Publication Date: 2014-01-01

Volume: Unknown

Issue: Unknown

Page Range: 78-84

Description:

Airlines are constantly looking for ways to cut flight delays, in order to enhance service quality and reduce operational costs. The goal of the data science contest, GE Flight Quest (https://www.gequest.com/c/flight), was to make flights more efficient by improving the accuracy of arrival time estimates. The data set of the contest was 128 GB in size and contained 252 data columns arranged in 34 tables. This paper presents my solution that won third prize under team name Taki. The solution employs a 6-stage model consisting of successive ridge regressions and gradient boosting machines, built on 56 features constructed from the raw data. The hardware environment used for training and running the model was a 64 core machine with 1 terabyte of memory.

Open Access: Yes

DOI: 10.1109/BigData.2014.7004435

Is early smoking a fashion trend or a defensive mechanism? - Study on consumer behaviour among students

Ida Ercsey Péter Huszka László Józsa

Publication Name: Economics and Sociology

Publication Date: 2014-01-01

Volume: 7

Issue: 1

Page Range: 142-156

Description:

Health status in Hungary has been deteriorating since the mid-1960s, resulting that Hungary is behind the developed health cultures - mainly Western European - countries. Considering these facts, our scientific interest turned to the examination of health awareness, drinking and smoking habits, healthy lifestyles, state of health and environmental awareness of adolescents and youngsters. To realize these tasks, during the set-up of the sample our aim was to provide representativeness and randomness. The research found that those pupils, who had a harmonious relationship with their parents, maintained a lower level (substance use) smoking and smoking frequency characteristic. No less important is the observation that youngsters try the cigarettes more and more early, but they are far too optimistic in assessing their own health.

Open Access: Yes

DOI: 10.14254/2071-789X.2014/7-1/13

Modeling integrated sustainable waste management systems using fuzzy cognitive maps and systems of systems concepts

Miklós F. Hatwágner Adrienn Buruzs L. T. Kóczy

Publication Name: Civil Comp Proceedings

Publication Date: 2014-01-01

Volume: 105

Issue: Unknown

Page Range: Unknown

Description:

Movement towards more sustainable waste management practice has been identified as a priority in the whole of the EU. The EU Waste Management Strategy's requirements emphasizes waste prevention; recycling and reuse; and improving final disposal and monitoring. Integrated waste management systems can be defined as the selection and application of suitable and available techniques, technologies and management programs to achieve waste management objectives and goals. As a result of the complexity and uncertainty occurring in sustainable waste management systems, the fuzzy cognitive map method is used with the combination of the bacterial evolutionary algorithm to support the planning and decision making process of integrated systems. Since the fuzzy cognitive map method is formed for a selected system by determining the concepts and their relationships, it is possible to quantitatively simulate the system considering its parameters. Several techniques were used in order to produce the input data of the simulation process. The goal of this paper is to present the process of data production.

Open Access: Yes

DOI: DOI not available

Phase-field modeling of polycrystalline solidification: From needle crystals to spherulites - A review

Attila Szállás László Környei László Rátkai Bálint Korbuly Tamás Pusztai László Gránásy Gyula I. Tóth

Publication Name: Metallurgical and Materials Transactions A Physical Metallurgy and Materials Science

Publication Date: 2014-01-01

Volume: 45

Issue: 4

Page Range: 1694-1719

Description:

Advances in the orientation-field-based phase-field (PF) models made in the past are reviewed. The models applied incorporate homogeneous and heterogeneous nucleation of growth centers and several mechanisms to form new grains at the perimeter of growing crystals, a phenomenon termed growth front nucleation. Examples for PF modeling of such complex polycrystalline structures are shown as impinging symmetric dendrites, polycrystalline growth forms (ranging from disordered dendrites to spherulitic patterns), and various eutectic structures, including spiraling two-phase dendrites. Simulations exploring possible control of solidification patterns in thin films via external fields, confined geometry, particle additives, scratching/piercing the films, etc. are also displayed. Advantages, problems, and possible solutions associated with quantitative PF simulations are discussed briefly. © 2013 The Minerals, Metals & Materials Society and ASM International.

Open Access: Yes

DOI: 10.1007/s11661-013-1988-0

Finite element modeling and identification of metallic materials step responses

Zoltán Pólik Zoltán Kántor

Publication Name: COMPEL the International Journal for Computation and Mathematics in Electrical and Electronic Engineering

Publication Date: 2014-01-01

Volume: 33

Issue: 6

Page Range: 1920-1934

Description:

Purpose - The purpose of this paper is to study the optimization of a pulsed-excitation gradiometric inductive sensing system. Design/methodology/approach - The authors applied numerical finite-element modeling for the simulation of the step responses of different target materials to identify the particular contribution of the magnetic permeability and the electric conductivity. Four materials of technical importance (aluminum, copper, constructional steel and stainless steel) and four fictive test materials were modeled for the comparison of different materials possessing a wide range of combinations of material parameters. A microcontroller-based measurement setup was implemented for the qualitative validation of the simulation results. A simple signal processing chain was also applied for the time-domain conversion of the direct step response signals to increase the time scale of the signals to be processed by common mixed-signal components. Findings - The step response signals contain relevant information of the target material quality and the sensor-to-target distance. The target materials can be distinguished and the sensor-target distance can be determined by the evaluation of the step response signals with an appropriate algorithm based on the measurement of the time and voltage of an extreme of the time dependent measurement signals. Both direct and time-domain converted signals can be used for material independent proximity sensing. Originality/value - In order to design an inductive proximity switch, an evaluation method of the response signals has been proposed by using an analog RLC circuit. With the presented method, a target material invariant inductive proximity switch can be realized.

Open Access: Yes

DOI: 10.1108/COMPEL-11-2013-0349