Periodica Polytechnica archív cikkek

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Derivation of Equations for Conductor and Sag Curves of an Overhead Line Based on a Given Catenary Constant
(Budapest University of Technology and Economics, 2014) Hatibovic, Alen
When the spans of an overhead line are large (for instance over 400 metres) the conductor curve cannot be considered as a parabola, since in that case the difference in comparison to the catenary cannot be neglected. At such times the exact calculation has to be applied, i.e. the conductor curve has to be considered as a catenary (hyperbolic cosine). The catenary based calculation does not have limitations, it can be used for small and large spans as well, but in comparison to the parabola method it is significantly more complicated. This article shows the way of derivation of new equations for the conductor and sag curves based on a known catenary constant, which refers to the chosen conductor type, span length, tension and temperature of the overhead line. The shown formulas ensure exact computing of the conductor height and sag at any point of the span, avoiding errors generated by the approximation of the catenary by a parabola.
LDV measurements of Newtonian and non-Newtonian open-surface swirling flow in a hydrodynamic mixer
(Budapest University of Technology and Economics, 2013) Csizmadia, Péter; Hős, Csaba János
The aim of this paper is to study the cyclone-like flow inside a hydrodynamic mixer experimentally, with a special emphasis on the differences in the flow field in the case of Newtonian and non-Newtonian fluids. The mixer consists a cylindrical body with conical bottom, in which two, tangentially entering fluid jets drive the rotating motion of the fluid body. The two fluids are (1) water and (2) a Carbopol solution obeying power-law rheology. The circumferential and axial velocity distributions were measured with the help of LDV for several fluid levels and driving flow rates. We show that in the case of water, the velocity distributions are qualitatively similar for several flow rates if the fluid height is kept constant. In the case of the power-law fluid, the measured velocity profiles show less generality.
Corner Detection and Classification of Simple Objects in Low-Depth Resolution Range Images
(Budapest University of Technology and Economics, 2013) Kovács, Viktor; Tevesz, Gábor
This paper deals with corner detection of simple geometric objects in quantized range images. Low depth resolution and noise introduce challenges in edge and corner detection. Corner detection and classification is based on layer by layer depth data extraction and morphologic operations. Appearance based heuristics are applied to identify different corner types defined in this paper. Both computer generated and captured range images are dealt with. Synthetic range images have arbitrary range resolution while captured images are based on the sensor used. Real world data is collected using a structured light based sensor to provide dense range map.
Nonholonomic Path Planning for a Point Robot with Car-Like Kinematics
(Budapest University of Technology and Economics, 2013) Kiss, Domokos; Tevesz, Gábor
A new approach of nonholonomic path planning for car-like robots is presented. The main idea is similar to many existing approaches which obtain a path in two phases. It is familiar in nonholonomic planning that at first a holonomic path is planned which is approximated by a nonholonomic one in a second step by subdividing it into smaller parts and replacing them with local paths fulfilling the kinematic constraints. These methods mostly rely on probabilistic methods and heuristic optimization. Our approach uses a holonomic preliminary path as well, but it serves only as a "loose guidance" to the second phase of the planning process. The final path is not required to contain any of the intermediate points of the preliminary path at all. The method is effective in environments consisting of narrow corridors but having wider free areas as well which can be used for maneuvering.
Compensation of Analog-to-Digital Converter Nonlinearities using Dither
(Budapest University of Technology and Economics, 2013) Renczes, Balázs; Kollár, István
Analog-digital converters are inherently nonlinear. Conventional A/D conversion allows no real remedy afterwards. However, an alternative is to increase the available information by observing the transition instants, even with a conventional ADC. Performing the conversion with significant oversampling data points at threshold level crosses can be used. The values of these samples are precisely known, assuming histogram test was executed on the ADC beforehand. For almost constant signals having too few transition level crossings, dither is added. Interpolation is utilized to ensure uniformly sampled data points. This method reduces the conversion error considerably.
Communication Time Estimation in High Level Synthesis
(Budapest University of Technology and Economics, 2013) Pilászy, György; Rácz, György; Arató, Péter
The high level synthesis (HLS) tools may result in a multiprocessing structure, where the time demand of the interchip data transfer (briefly the communication) between the processing units (hardware or software) is determined exactly only after the task-allocation. However, a realistic preliminary estimation of the communication time would help to shape the scheduling and the allocation procedures just for attempting to minimize the communication times in the final structure. Compared to the task-execution times of the processing units, especially significant communication times are required by the serial communication interfaces which are frequently used in microcontroller systems. This paper presents an estimation method by analysing four well-known serial communication interfaces (SPI, CAN, I2C, UART).
Formation Control of Quadrotor Helicopters with Guaranteed Collision Avoidance via Safe Path Planning
(Budapest University of Technology and Economics, 2012) Regula, Gergely; Lantos, Béla
In this article we propose a hierarchical control structure for multi-agent systems. The main objective is to perform formation change manoeuvres, with guaranteed safe distance between each two vehicles throughout the whole mission. The key components that ensure safety are a robust control algorithm that is capable of stabilising the group of vehicles in a desired formation and a higher level path generation method that provides safe paths for all the vehicles, based on graph theoretic considerations. The method can eﬃciently handle a large group of any type of vehicles. In the article we focus on the control of quadrotor UAVs, thus the results are illustrated in 4D on a group of such vehicles.
Stable Object Grasping With Dextrous Hand In Three-Dimension
(Budapest University of Technology and Economics, 1999) Tóth, Ervin
This paper considers a grasp planning scheme for dextrous hands. The grasp is assumed to be a preciseone, which means that only the fingertips of the hand are in contact. The most important algorithm ofthe grasp planner is the placement of contact points in the presence of friction. Based on a heuristicsearch, a number of grasp configurations are generated. A proposed method for evaluation of theconfigurations and determination whether a grasp is a force closure, is introduced. These algorithmsare used in the experimental control system of an industrial robot, which the dextrous hand is attachedto. A two-level robot programming language, which was written for the robot-hand system, is brieflyintroduced.
Replaying Execution Trace Models for Dynamic Modeling Languages
(Budapest University of Technology and Economics, 2012) Hegedüs, Ábel; Ráth, István Zoltán; Varró, Dániel
Back-end analysis tools aiming to carry out model-based veriﬁcation and validation of dynamic behavioral models frequently produce sequences of simulation steps (called execution traces) as their output. In order to support back-annotation of such traces, we need to store and replay them within a modeling environment (outside the analysis tool). In the paper, we present a technique for replaying recorded execution traces of dynamic modeling languages. Our approach complements static and dynamic metamodels by introducing a generic execution trace metamodel which is used to replay completed executions of a simulation directly over the dynamic model. Furthermore, we present a technique to drive a simulation according to execution trace models. Our approach will be exempliﬁed by the modeling language and trace information of the SAL model checker and BPEL business processes.
Basins of attraction in a harmonically excited spherical bubble model
(Budapest University of Technology and Economics, 2012) Hegedűs, Ferenc; Kullmann, László
Basins of the periodic attractors of a harmonically excited single spherical gas/vapour bubble were examined numerically. As cavitation occurs in the low pressure level regions in engineering applications, the ambient pressure was set slightly below the vapour pressure. In this case the system is not strictly dissipative and the bubble can grow infinitely for sufficiently high pressure amplitudes and/or starting from large initial bubble radii, consequently, the stable bubble motion is not guaranteed. For moderate excitation pressure amplitudes the exact basins of attraction were determined via the computation of the invariant manifolds of the unstable solutions. At sufficiently large amplitudes transversal intersection of the manifolds can take place, indicating the presence of a Smale horseshoe map and the chaotic behaviour of system. The incidence of this kind of chaotic motion was predicted by the small parameter perturbation method of Melnikov.
Thermal simulation of a pin on a rotating cylinder jacket system
(Budapest University of Technology and Economics, 2012) Bódai, Gábor; Váradi, Károly; Szücs, János; Szabó, András; Zobory, István
In this paper specimen level measurements and finite element simulations are introduced in order to study the thermal behaviour of a pin and wheel sliding contact configuration. The pin-like specimen is processed from cast iron and models the local contact of a railway brake block and wheel tire. The sliding contact is treated in the framework of a 3 dimensional problem in order to achieve reliable results. The paper also treats with the heat partition problem by distributed heat source and moving heat source models. The results are compared to measured datas and show that the classical heat partition approach is not valid for the friction pair examined i.e. the contact. However authors determine the exact heat partition ratio by an iterative approach and give explanations on the experienced temperature differences.
Time-optimal computed-torque control in contact transitions
(Budapest University of Technology and Economics, 2012) Magyar, Bálint; Stépán, Gábor
The simple mechanical model of an approach-and-touch control procedure is discussed. The aim is to find an appropriate control strategy to approach the target surface, handle the contact transitions and apply the desired force on the contact surface. In the control loop, position and force feedback is present; the absolute position of the target surface is only available for the controller with limited accuracy.
A Model Predictive Navigation Approach Considering Mobile Robot Shape and Dynamics
(Budapest University of Technology and Economics, 2012) Kiss, Domokos; Tevesz, Gábor
Most mobile robot navigation approaches assume the robot being point-like or consider only its bounding circle while looking for a collision-free path to a given goal position. A well-known method called the Dynamic Window Approach (DWA) introduced an interesting idea for solving the navigation problem by local optimization in the control space of the robot. Some extensions of the original DWA method can also be found in the literature, which enable its applicability to holonomic and non-holonomic robots and ensure a global and safe solution to the navigation problem. The method described in this paper has also been motivated by the basic idea of dynamic window and contributes to the previous variants by taking the robot shape into consideration as well. A navigation function based model predictive control scheme is utilized to choose the appropriate control for a safe and successful navigation.
Data fusion and primary image processing for aircraft identification
(Budapest University of Technology and Economics, 2012) Lukács, Loránd; Lantos, Béla
The primary scope of this study lays on system technique solutions of collecting data required for the identiﬁcation of an aircraft’s nonlinear dynamic model. It is assumed that the aircraft has no inbuilt navigational system, nor any sensors mounted on its control surfaces. The control column and pedals manipulated by the pilot can only visually be observed. For the time of data logging, an external sensory system (GPS, IMU) and a camera system were deployed on the airplane supporting the collection of ﬂight data. The paper presents the data acquisition solutions required for aircraft’s nonlinear model identiﬁcation, with an emphasis on the determination of the control surface positions as the system’s input signals using image processing. During ﬂight, the control column and pedal positions manipulated by the pilot are recorded using a video camera and with post processing, data is converted to control surface (rudder, elevator, aileron) positions. The 3D positions of the pilot’s control column are determined from 2D pixel values. The input signals are then calculated using this information and the control surface characteristics. The input signals and state variables determined with a state estimator are regarded as input signals for the identiﬁcation of an aircraft’s nonlinear model.
Natural conditions in the Carpathian Basin of the Middle Ages
(Budapest University of Technology and Economics, 2007) Rabb, Péter
The analysis of natural conditions is a new field in Hungarian medieval research. This field could only come into existence with the spread of new sources of research, and with the need of drawing the most realistic picture of medieval living conditions with the help of more - previously ignored - data and facts. This field of research may have a special meaning as according to sources of the age, the Carpathian Basin was one of the natural Paradises of Medieval Europe.
Feasibility of Real-time Available Transfer Capacity Calculations with PSSE
(Budapest University of Technology and Economics, 2010) Decsi, Tamás Gábor; Dán, András
A new procedure is reviewed in this article that offers the possibility of the precision enhancement of intra-day network capacity calculations. The main advantages of the new procedure are the calculation capability of potential Emergency Assistance Service in reasonably short time and the enhancement of the intra-day trading activities.
Integral Calculus Usage for Conductor Length Determination on the Basis of Known Maximal Sag of a Parabola
(Budapest University of Technology and Economics, 2012) Hatibovic, Alen
This paper shows a mathematic solution for calculation of conductor length using integral calculus on a parabola. The presented method can be used for spans approximately up to 400 metres. In that case the catenary may be approximated by a parabola (quadratic function), while the diﬀerence between the catenary and the parabola is negligible. The necessary data are the span length, the heights of the suspension points and the value of the maximal sag. The algorithm is prepared for in- clined spans, but it is applicable for levelled spans too, because it is just one special case when the conductor suspension points on two supports are on the same height level. Naturally, the conductor length changes with temperature, so it is possible to calculate it for a chosen temperature, using a conductor sag for that temperature, chosen tension and conductor type.
Experimental and numerical study on cavitating vortex shedding behind a square cylinder
(Budapest University of Technology and Economics, 2009) Hegedűs, Ferenc; Roland Rákos; Kullmann, László
Comparison between experimental and numerical results of the cavitating vortex shedding behind a square cylinder is presented. The side length of the experimental and numerical model was 25 mm and 20 mm, respectively. The water velocity in the 0.2x0.05 m test section of the channel was varied between 1 and 12 m/s resulting in a Reynolds number range of (0.4-3.5)x10^5. In the simulation the mean velocity was increased up to 14 m/s with 1 m/s increment. Dominant frequencies and Strouhal numbers are reported from cavitation-free flow (classical von Kármán vortex shedding) up to supercavitation as a function of the free-stream Reynolds number. It was found that between the inception of cavitation and the formation of supercavitation the Strouhal number is not affected by cavitation. The results are in a fairly good agreement with the literature.
Information System for Road Infrastructure Booking
(Budapest University of Technology and Economics, 2011) Soltész, Tamás; Kózel, Miklós; Csiszár, Csaba; Centgráf Tamás; Benyó, Balázs István
Booking of road infrastructure is a tool for management of„stresses” between traffic demand and available infrastructurecapacity (supply). In this course entitlement to use of certainnetwork elements (lane, zone, and parking lot) can be pur-chased. It can be applied at those network elements where trafficjams are generated regularly and travel time is unpredictable.Charges for use of infrastructure are proportional to the num-ber of bookings. Its extent influences both travel mode and ve-hicle choice. „Intervention” in traffic flows is wanted, there-fore its analysis and control require the use of knowledge in thefollowing fields: transport network planning, traffic technologyand transport informatics; in a system- and process-oriented ap-proach. Model of this complex transport system has been builtup; the operations are influenced by dynamic information.
How can corporate competence be measured?
(Budapest University of Technology and Economics, 2010) Laáb, Ágnes
This paper is about the phenomenon that competence assets never manifest in their whole magnitude and worth. Due to this fact, we do not have complete and fully reliable information about their real magnitude, either in quantity or value. And yet, this may not give an excuse not to look into this matter and not to manage this important and increasingly significant asset in accordance with its - specific - worth! The competence assets of a company consist of two parts: partly the competence synergy made up of the employees´ cooperation, relations, joint successes and failures, and partly that part of the personal competences of employees, by which they generate value for the company. It is expected that from the scope of competence assets, asset items similar to intellectual assets can be removed and then turned into tangible assets (they can be separated from the person who created them) and because they meet the balance sheet criteria, they become appraisable as independent asset items. Such factors can be, for example, the customer value and the customer lifetime value in the case of such servicing companies, where the customers take the commitment for an undefined period of time, but for a longer term anyway to make use of the company´s services on a monthly basis. In such cases customer relations are prioritised as corporate resources having an independent value. In this paper, however, we are focusing on those flow items of the competence assets, which are difficult to alienate from employees.
Optimization of Fluidic Microchannel Manufacturing Processes in Low Temperature Co-Fired Ceramic Substrates
(Budapest University of Technology and Economics, 2010) Horváth, Eszter Edit; Harsányi, Gábor
The processing of starch powder and polymer based sacrificial layer for fabrication of microfluidic structures in low temperature co-fired ceramics (LTCC) is described in the paper. Sacrificial volume material (SVM) was placed into the channel of LTCC sheets to avoid sagging by supporting embedded, three-dimensional structures such as channels, cavities during firing. Sagging of laminated structures is a common problem in the processing of the LTCC. A series of experiments were carried out for different lamination schemes which affect the quality of LTCC sheets. Samples were tested by an acoustic microscope to reveal the internal inhomogeneities and delaminations. As a consequence of burnout, the increased fraction of evolving gases from SVM requires an adequate adaptation of the firing process to provide a residue-free burnout without damaging the structure. Using thermal analysis the intensity of the evaporating gases was determined during co-firing. Based on these results, the modification of the heating profile could be done. It is proposed that the fabrication of embedded structures in a multi-layer LTCC platform could be achieved by controlling SVM burnout with a modified heating profile. Using this approach, fabrication of embedded channels in LTCC substrate is demonstrated.
Synchronization and Sampling in Wireless Adaptive Signal Processing Systems
(Budapest University of Technology and Economics, 2010) Orosz, György; Sujbert, László; Péceli, Gábor
This paper deals with the synchronization in wireless adaptive signal processingsystems. Wireless communication offers high flexibility, however, the distributedstructure of wireless systems requires the synchronization of the subsystems. Thesynchronization becomes particularly important if the signal bandwidth is in thekHz range, and it is inevitable in distributed control systems. The demand on thesynchronization is presented through the introduction of awireless active noise con-trol system. In this system wireless sensors (microphones)receive the signal, and themain signal processing algorithm is implemented on a central unit which producesthe signal for the actuators (loudspeakers). In spite of thespecial application, thesystem has a general structure, so the results are valid for other adaptive systems.First a PLL like algorithm is described for the synchronization of the sampling ina wireless real-time signal processing system, then a higher-level synchronizationis introduced for a distributed Fourier-analyzer based noise control system. Theeffectiveness of the algorithms is demonstrated by measurement results.
Finding Multiple Redundant Trees in Linear Time
(Budapest University of Technology and Economics, 2010) Enyedi, Gábor Sándor; Rétvári, Gábor
Redundant trees are directed spanning trees, which provide disjoint paths towards their roots. Therefore, this concept is widely applied in the literature both for providing protection and load sharing. The fastest algorithm can find multiple redundant trees, a pair of them rooted at each vertex, in linear time. Unfortunately, edge- or vertex-redundant trees can only be found in 2-edge- or 2-vertex-connected graphs respectively. Therefore, the concept of maximally redundant trees was introduced, which can overcome this problem, and provides maximally disjoint paths towards the common root. In this paper, we propose the first linear time algorithm, which can compute a pair of maximally redundant trees rooted at not only one, but at each vertex.
Some organizational issues of technology roadmapping experienced in Hungary
(Budapest University of Technology and Economics, 2010) Pataki, Béla; Szalkai, Zsuzsanna; Bíró-Szigeti, Szilvia
Technology roadmapping (TRM) is a technique for exploring the evolution of markets, products, technologies, and their linkages. During our Hungarian TRM-applications we found important a clear business need; senior level ownership; effective communication; information and knowledge sharing; spending considerable time at the beginning; preferring less frequent but longer workshops than more frequent shorter ones; involving all related functions, active participation of senior managers; having a TRM-champion inside the company; a case-study-based training to teach TRM; and calling TRM a different name at the beginning.
Uncertainty in innovation in the biotech-pharmaceutical industry
(Budapest University of Technology and Economics, 2010) Domonkos, Dávid
Biotechnology, just like other dynamically growing branches of industry, has been very rapidly changing. Disruptive innovations arise from time to time. Since this is a very high risk - high benefit industry, and R & D phases often require several hundred millions of dollars, the participants seek to minimize and share risk. In case of biotechnology the assessment of risks (uncertainties) in the technological development is becoming an increasingly difficult task to solve. This is especially true in a rapidly changing turbulent environment, where environment and its knowledge changes from day to day, where in addition to small ones, radical innovations are typical as well. Understanding the necessary parameters is becoming more and more uncertain, thus also becoming limited. There is a huge literature on technological uncertainty just as there is on risks of financial issues. My main problem with this is that there is a strong inclination to believe that uncertainty can always be successfully modelled by quantitative risk assessment (qRA). In contrast to this, a wide range of environmental studies puts emphasis on the non-predictable risk. (Think of the the management consequence of non-predictability, the needed precaution.) A small biotech company has two alternatives for survival: finding a protected market, where, drawing on resources from outside, it can become influential, or by concentrating on cooperation, solving a partial task, working as part of a cluster, becoming an importer of knowledge.
Analytical and simulation comparison of sinusoidal and resistive modulation strategies for network-friendly three-phase grid-connected inverters
(Budapest University of Technology and Economics, 2010) Balázs, Gergely György; Schmidt, István; M. Horváth
The growing numbers of consumers distort AC networks with harmonics. Therefore suppression of the network pollution should be considered. This problem can be solved by using ``network-friendly´´ converters. In our study we examined two modulation strategies of three-phase grid-connected inverters. If these methods are used, converters behave like sinusoidal or resistive current loads of the network, which enables ``network-friendly´´ operation. The examined sinusoidal and the resistive modulation strategies are known, but the differences between the two methods have not been studied before [1,2]. This paper deals with the comparison of these two strategies. First, the analytical examination is presented. By comparing their consumed RMS currents we defined a coefficient (k[%]), which depends only on the total harmonic distortion of the network voltage (THD_u). We demonstrated that at high THD_u resistive modulation method is more favorable. Then simulation examination is discussed, by presenting our model of the three-phase four quadrant converter. Finally simulation results are represented in this article.
Revised Transient Stability Index For Smart Grids
(Budapest University of Technology and Economics, 2010) Vokony, István; Dán, András
In this paper the physical concept, calculation method and application possibilities of a novel stability index are briefly summarized. The details of the calculation method resulting in a better characterization of the dynamic security of the power system are published. The aim of our work is to develop a stability index for filtering stability calculation cases made for network development planning and to provide a possibility of real-time stability monitoring for power system dispatchers. Simulation results of model network are described, conclusions are drawn and evaluated.
Test Component Assignment and Scheduling in a Load Testing Environment
(Budapest University of Technology and Economics, 2008) Erős, Levente; Bozóki, Ferenc
In this paper we introduce two major problems from the field of load (or performance) testing and our solutions for them. When testing the performance of a device (System Under Test - SUT), the test environment executes many software entities (the so-called test components) on the hosts of the test environment (testing hosts). Our goal is to maximize the load on the testing hosts by assigning the test components to them closely to optimal. The first problem to be solved is, thus, a special case of the task assignment problem for which many algorithms have been developed. Our solutions presented in this paper are, however, optimized for distributing load testing traffic in the case of which the possibilities and restrictions to be taken into account are very different from those of the classical task assignment case. The other problem we deal with is how to schedule test components running on the same testing host. Most of the papers written on scheduling focus on the characteristics of the generated load, bu t not on the way of generating it. These papers usually assume that the load can be generated by improving hardware resources. In this paper, however, we introduce a model and an algorithm which improves the efficiency of scheduling in a load testing environment with way less hardware resources. The algorithm is based on our novel concept of virtual threads. Our simulations have shown that by applying our solutions, the efficiency of load testing can be significantly increased.
Backstepping Based Control Design with State Estimation and Path Tracking to an Indoor Quadrotor Helicopter
(Budapest University of Technology and Economics, 2010) Regula, Gergely; Lantos, Béla
The article focuses on different aspects (both theoretical and practical) of the development of the control algorithm of a quadrotor helicopter starting from the modelling phase. A new control algorithm is elaborated and supplementary components are described in detail including state estimation and path tracking. The helicopter´s dynamic model takes into account the aerodynamic friction, the gyroscopic effect of the rotors and also the motor dynamics. The control algorithm is based on the backstepping approach and is capable of stabilising the model even in case of realistic noises. Vision system and on-board inertial measurement unit provide the measurements and two-level extended Kalman filter based state estimator is used to suppress the measurement noises and to estimate the unmeasured signals. The methods of the software development and real-time testing are also presented with attention to the sources of common errors.
Extracting geometric information from images with the novel Self Affine Feature Transform
(Budapest University of Technology and Economics, 2010) Prohászka, Zoltán Ferenc; Lantos, Béla
Based on our research, the Self Affine Feature Transform (SAFT) was introduced as it extracts quantities which hold information of the edges in the investigated image region. This paper gives details on algorithms which extract various geometric information from the SAFT matrix. As different image types should be analysed differently, a classification procedure must be performed first. The main contribution of this paper is to describe this classification in details. Information extraction is applied for solving different 2-dimensional image processing tasks, amongst them the detection of convergent lines, circles, ellipses, parabolae and hiperbolae or localizing corners of calibration grids in a robust and accurate manner.
Beyond the Limits of Kinematics in Planning keyframed Biped Locomotion
(Budapest University of Technology and Economics, 2010) Juhász, Tamás; Urbancsek, Tamás
Keyframed motion planning is a technique that specifies a robot motion by its joint variable samples in discrete time-steps. In this paper, we aim to provide an off-line (i.e. non real-time) dynamic motion optimizing method for keyframed humanoids. Let´s assume that a desired reference movement has been designed, it can be simulated using a real-time kinematics model. Due to dynamic effects the robot segments will not exactly follow the reference trajectories. Assuming a detailed, sophisticated dynamics model (running offline) we can formulate a norm that expresses the difference of dynamic and kinematic simulations. In this article we present our idea, how the motion could be automatically tailored by lowering this norm using numerical methods in a way, that the output of the dynamic model better approximates the reference motion. Finally, we show our experimental results within a modern simulation environment as well as on our test humanoid platform.
Integration of the Sustainability concept into Strategy and Marketing.
(Budapest University of Technology and Economics, 2004) Vágási, Mária
The paper reviews how recent marketing concepts reflect sustainability requirements and competitiveadvantages of their integration into mission, strategy and policies at companies. Marketing approachof sustainability is discussed through the concepts of added value delivery to customers, societalmarketing and customer relationship marketing. The discussion is extended to some related strategicand management implications as well.
Subsidies in automotive industry
(Budapest University of Technology and Economics, 2007) Kemenczei, Nóra
In my essay I am going to examine the experiences of the National Development Plan I. This scheme is a document that concerns the development strategy of Hungary for the first three years´ planning after joining the European Union (2004-2006). I concentrate on the short period effects on economy, and I focus on the specific purposes of a more competitive economy. I am also aiming at a short introduction of the objectives and the priorities of the Competitive Economy Operative Programme (CEOP) I lay special emphasis on the first three priorities of CEOP: investment incentives, improvement of small-and-middle-size enterprises (SME) and R & D. I skirt the issue of the fourth priority - the improvement of a society and an economy based on information - as the direct economic effects of the purposes can not be monitored in that field. By my analysis I am seeking the answers for the question: what is the amount of financial support for the enterprises dealing with automobile industry - both in absolute and relative terms - from the provided frame of HUF 112,5 billion; and moreover: what are those structural short-term economic effects that can lead to the achievement of the objectives.
Thermal comfort of closed spaces. Fundamentals of static and dynamic heat balance of human body
(Budapest University of Technology and Economics, 2009) Bartal, Imrich; Bánhidi, László
The growing mechanization and industrialization of society has resulted in most people spending greater part of their lives - 85-90% - in artificial climate. In this climate, thermal comfort can be basically predicted by the environment parameters such as temperature, humidity, air velocity and by the personal parameters as activity and clothing resistance. This paper intends to present the basic equations of the classical comfort theory, the equations of the human body´s static heat balance, and the so called comfort equation as well as its sensitivity depending on the thermic parameters of the microclimate. The PMV expression describs the thermal comfort of the human body and its sensitivity. The concept of dynamic thermal sensation and the possibilities of its research will be introduced.
Fetal Pulse Oximeter for In Situ Monitoring during Labour and Birth
(Budapest University of Technology and Economics, 2008) Becker, Ákos Ferenc; Harsányi, Gábor
The oxygen saturation of arterial blood which is normally measured by pulse oximeters is highly important. This paper introduces a miniaturization development of a non-invasive, reflective pulse oximeter. The aim of the project is to dramatically reduce the dimensions of a current device developed earlier already on the market whose size is 41x23x12 mm (LxWxH). A further purpose is to invent a pulse oximeter which can be used to constantly monitor the oxygen saturation of a fetus during its birth and the labour period. Although similar devices can be found on the market, our oximeter is smaller in size and there is no connection cable which can cause discomfort to the mother. This objective has been achieved by changing the main components of the prototype. Also, the Bluetooth module has been changed to an energy saving RF communication device. The main controller is also improved by adding a nanoWatt series QFN packaged PIC microcontroller to reduce power consumption. All of the analog electronic parts have been integrated into an ASIC (Applications Specific Integrated Circuit) chip. In addition to improvements in the hardware, new control software has been written. This reshuffling means that a new evaluation board has been made for testing and controlling the newly designed oximeter. It is also easy to use. In addition, a conventional PC can be used for data display and processing which highly reduces the cost.
Aspect-Oriented Modelling and Analysis of Information Systems
(Budapest University of Technology and Economics, 2007) Majzik, István; P Domokos
In this paper we introduce an approach of aspect-oriented modelling and analysis of information systems. First we give an overview of the concepts of Aspect Oriented Programming and provide an outlook to model aspect-oriented programs. On the basis of this introduction, we describe a method of using aspects at the modelling level and weaving them into a single integrated model. Finally, we extend this framework with the automatic construction of analysis models based on separate aspect models. In our example, fault tolerance structures are modelled by aspects and the analysis model is a dependability model that is used to determine the non-functional properties of the system like reliability and availability. In this way the separate design of the functionality and the dependability is supported and the design decisions concerning fault tolerance can be analysed on the basis of the dependability model.
3SC Control for high efficiency grid connected photovoltaic converters
(Budapest University of Technology and Economics, 2009) Balogh, Attila; Varjasi, István
Nowadays there are several grid connected converters in the grid system. These grid connected converters are generally the converters of renewable energy sources, industrial four quadrant drives and other converters with DC link. These converters are connected to the grid typically through a three phase IGBT bridge. The standards prescribe the permissible maximal harmonic emission and the maximal reactive current for the grid connected converters. For a converter working at nominal power these two prescriptions together mean almost unity power factor. The harmonic emission could be easily limited with high switching frequency and/or with large harmonic filters. Further financial viewpoints are the efficiency, the small size and weight. Comparing to traditional control these requirements can be simultaneously satisfied much better with the 3SC (three state control) method. At 3SC we utilize all the three allowed state of one arm of the IGBT bridge, i.e. upper part conducting, lower part conducting, none of the m conducting.
Impact of Business Culture on Empowerment
(Budapest University of Technology and Economics, 2008) Andó, Ildikó
If a Hungarian´s father for example is Dutch and his mother is French, it gives him an understanding of the fact that if something works in one culture, there is a little chance that it will work in another. The situation is the same in business life. If something works in a traditional company culture, there is no evidence that it will work in a modern organization. Consequently, if a leader wants to be successful in leadership, he has to know the values of his team in detail. Several international and Hungarian researches mapped the Hungarian´s characteristics. Researchers claim, that national culture is in strong connection with company culture. According to this theory, company culture determines efficient leadership techniques. The author of this publication conducted an online survey with 324 respondents of two multinational companies. The main topic of the survey was to examine the relationship between organizational culture and the potentials of applying empowerment. Based on the results of the survey this study reveals the main cultural elements of companies and shows what kind of leadership methods can be used efficiently in special organizational circumstances.
Modelling and Calculating the Harmonic Penetration of the High Power Traction Usind the Double Domain Simulation
(Budapest University of Technology and Economics, 2009) Kiss, Péter; Dán, András
The paper presents the results of a long term research work. The authors are modelling the penetration and elimination of harmonic disturbance originating from the high power railways. This kind of problem is usually handled using time domain or frequency domain simulation. As it is well known, the modelling of harmonic sources is more accurate in time domain simulation, while the frequency dependence of the passive network is more accurate in frequency domain. That is why a novel method was developed named double domain simulation method, which is a combination of frequency and time dependent models. To calculate the sophisticated model of the electric locomotive as a non-linear load a time dependent model must be used. The traction supply system together with the equivalent supply network impedance could be calculated accurately in frequency domain. An iteration algorithm is developed converting the variables in every iteration step between the time and frequency domain. The application of the double domain simulation method to solve the harmonic filtering of high power railway system is introduced. The results prove that the method is suitable for studying the effect of different filtering methods, like the passive, active and hybrid filtering.
Designing a Tracking Controller for Passenger Cars with Steering Input
(Budapest University of Technology and Economics, 2008) Gincsainé Szádeczky-Kardoss, Emese; Kiss, Bálint
The results presented in the paper were motivated by a practical application. The goal was to design a parking assist system for a passenger car such that the assist is realized by controlling the steering wheel while the human driver handles the pedals (throttle, clutch and brake pedals) of the vehicle and thus generates its velocity. The tracking control of the car with the single steering input is achieved by a novel time-scaling based controller. The solution was tested in simulations and also in a real vehicle.

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