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Search Results: 1 - 10 of 189734 matches for " G. Kost "
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The comparison of elastic band and B-Spline polynomials methods in smoothing process of collisionfree robot trajectory
D. Reclik,G. Kost
Journal of Achievements in Materials and Manufacturing Engineering , 2008,
Abstract: Purpose: The main reason of this paper was to prepare the system, which tests the use of elastic band for smoothing the collision-free trajectory. The aided robot off-line programming system is based on NURBS and B-Spline curves. Because there is a lot of information in references about using elastic band algorithm, authors decided to compare these two methods. The most important criterion in robotics is having the smoothest possible robot trajectory, so as a standard there the NURBS curves (C2 smooth class) were used.Design/methodology/approach: Pascal language compiler was used for research. All algorithms were coded in this programming language and compiled. Results were set in Microsoft Excel worksheet.Findings: Results show that calculations, which were made with B-Spline method, have taken less time than calculations based on elastic band curves. Moreover, the elastic band method gave the smoothest curves but only in geometrical sense, which is less important (the first and second derivate are not continuous, which is the most important issue in presented case). That is why it was found that using the B-Spline algorithm is a better solution, because it takes less time and gives better quality results.Research limitations/implications: The MS Windows application was created, which generates smooth curves (in geometrical sense) by marking the interpolation base points which are calculated by the collision-free movement planner. This application generates curves by using both presented methods - B-Spline and elastic band. Both of these curves were compared in regard of standard deviation and variance of B-Spline and elastic band.Practical implications: Because the elastic band algorithm takes a lot of time (three times longer than B-Spline) it is not used in the final application. The authors used B-Spline method to make smoother and optimized trajectory in application for off-line collision-free robot programming.Originality/value: This is a new approach, which describes the comparison between elastic band and B-Spline polynomials methods in collision-free robot trajectory.
The signal connections in robot integrated manufacturing systems
D. Reclik,G. Kost,J.?wider
Journal of Achievements in Materials and Manufacturing Engineering , 2007,
Abstract: Purpose: The main goal of this paper is that, the robot integrated manufacturing systems are more popular and useful in the industry. Moreover, the communication in those systems might be realized by many different data exchange solutions. Using this kind of solution causes the data exchange incompatibility. This paper deals with different ways in informatics connection of all of the components in robot integrated manufacturing system.Design/methodology/approach: Incompatibility is a result of usage many different communication systems between components in lathe center. The way of mutual signal connections were the target of researches.Findings: As a result of scientific work, the universal and compatible informatics connection system of the robot lathe center was created.Research limitations/implications: The project of the data exchange system is confined to PROFIBUS DP lan.Practical implications: The result of the researches was developing a technical element choice procedure of the data exchange depending on transport means quantity and system composition in the robot lathe system.Originality/value: This is a brand new paper, which describes internal systems of data exchange in robot integrated manufacturing system in example of automatic lathe center.
The signal connections in robot integrated manufacturing systems
D. Reclik,G. Kost,J. ?wider
Journal of Achievements in Materials and Manufacturing Engineering , 2008,
Abstract: Purpose: The main goal of this paper is that, the robot integrated manufacturing systems are more popular and useful in the industry. Moreover, the communication in those systems might be realized by many different data exchange solutions. Using this kind of solution causes the data exchange incompatibility. This paper deals with different ways in informatics connection of all of the components in robot integrated manufacturing system.Design/methodology/approach: Incompatibility is a result of usage many different communication systems between components in lathe center. The way of mutual signal connections were the target of researches.Findings: As a result of scientific work, the universal and compatible informatics connection system of the robot lathe center was created.Research limitations/implications: The project of the data exchange system is confined to PROFIBUS DP lan.Practical implications: The result of the researches was developing a technical element choice procedure of the data exchange depending on transport means quantity and system composition in the robot lathe system.Originality/value: This is a brand new paper, which describes internal systems of data exchange in robot integrated manufacturing system in example of automatic lathe center.
Adjustment method of parameters intended for first-principle models
P. Czop,G. Kost,D. S?awik,G. Wszo?ek
Journal of Achievements in Materials and Manufacturing Engineering , 2012,
Abstract: Purpose: This paper demonstrates a process of estimation phenomenological parameters of a first-principle nonlinear model based on the hydraulic damper system.Design/methodology/approach: First-principle (FP) models are formulated using a system of continuous ordinary differential equations capturing usually nonlinear relations among variables of the model. The considering model applies three categories of parameters: geometrical, physical and phenomenological. Geometrical and physical parameters are deduced from construction or operational documentation. The phenomenological parameters are the adjustable ones, which are estimated or adjusted based on their roughly known values, e.g. friction/damping coefficients. Findings: A phenomenological parameter, friction coefficient, was successfully estimated based on the experimental data. The error between the model response and experimental data is not greater than 10%.Research limitations/implications: Adjusting a model to data is, in most cases, a non-convex optimization problem and the criterion function may have several local minima. This is a case when multiple parameters are simultaneously estimated. Practical implications: First-principle models are fundamental tools for understanding, optimizing, designing, and diagnosing technical systems since they are updatable using operational measurements.Originality/value: First-principle models are frequently adjusted by trial-and-error, which can lead to nonoptimal results. In order to avoid deficiencies of the trial-and-error approach, a formalized mathematical method using optimization techniques to minimize the error criterion, and find optimal values of tunable model parameters, was proposed and demonstrated in this work.
Formulation and identification of First- Principle Data-Driven models
P. Czop,G. Kost,D. S?awik,G. Wszo?ek
Journal of Achievements in Materials and Manufacturing Engineering , 2011,
Abstract: Purpose: The paper consists of two parts. The first part presents and discusses a process of formulation and identification of First-Principle Data-Driven (FPDD) models, while the second part demonstrates numerical examples of identification of FPDD models.Design/methodology/approach: First-Principle (FP) model is formulated using a system of continuous ordinary differential equations capturing usually nonlinear relations among variables of the model. The considering model applies three categories of parameters: geometrical, physical and phenomenological. Geometrical and physical parameters are deduced from construction or operational documentation. The phenomenological parameters are the adjustable ones, which are estimated or adjusted based on their roughly known values, e.g. friction/damping coefficients.Findings: A few phenomenological parameters were successfully estimated from numerically generated data. The error between the true and estimated value of the parameter occurred, however its magnitude is low at level below 2%.Research limitations/implications: Adjusting a model to data is, in most cases, a non-convex optimization problem and the criterion function may have several local minima. This is a case when multiple parameters are simultaneously estimated.Practical implications: FPDD models are an excellent tool for understanding, optimizing, designing, and diagnosing technical systems since they are updatable using operational measurements. This opens application area, for example, for model-based design and early warning diagnostics.Originality/value: First-Principle (FP) models are frequently adjusted by trial-and-error, which can lead to non-optimal results. In order to avoid deficiencies of the trial-and-error approach, a formalized mathematical method using optimization techniques to minimize the error criterion, and find optimal values of tunable model parameters, was proposed and demonstrated in this work.
Automatic programming and generation of collision-free paths for the Mitsubishi Movemaster RV-M1 robot
K. Foit,G.G. Kost,D. Reclik
Journal of Achievements in Materials and Manufacturing Engineering , 2011,
Abstract: Purpose: of this paper: This paper discuss the possibility to develop and implementing the computer system, which could be able to generate a collision-free path and prepare the data for direct implementing in the robot’s program.Design/methodology/approach: The existing methods of planning of the collision-free paths are mainly limited to the 2D issue and implemented for the mobile robots. The existing methods for planning the trajectory in 3D are often complicated and time-consuming, so most of them are not introduced in reality, being only a theory. In the paper the 2 D method has been presented together with the method of smoothing the generated trajectory. Experiments have been carried out in the virtual environment as well as on the real robot.Findings: The developed PLANER application has been adapted for cooperation with the Mitsubishi Movemaster RV-M1 robot. The current tests, together with the previous one carried out on the Fanuc RJ3iB robot, have shown the versatility of the method and the possibility to adapt it for cooperation with any robotic system.Research limitations/implications: The further stage of research will be concentrated on the consolidation of trajectory generating and simulation phase with the program execution stage in such a way, that the determination of collision-free path could be realized in real time.Practical implications: This approach clearly simplifies the stage of defining the relevant points of the trajectory in order to avoid collisions with the technological objects located in the robot’s manipulator environment. Thereby it significantly reduces the time needed for implementation of the program to the production cycle.Originality/value: The method of generating the collision-free trajectories, which is described in the paper, combines some of the existing tools with the new approach to achieve the optimal performance of the algorithm.
Perfect state transfer in networks of arbitrary topology and coupling configuration
V. Kost'ak,G. M. Nikolopoulos,I. Jex
Physics , 2007, DOI: 10.1103/PhysRevA.75.042319
Abstract: A general formalism of the problem of perfect state transfer is presented. We show that there are infinitely many Hamiltonians which may provide solution to this problem. In a first attempt to give a classification of them we investigate their possible forms and the related dynamics during the transfer. Finally, we show how the present formalism can be used for the engineering of perfect quantum wires of various topologies and coupling configurations.
Towards a virtual Arabidopsis plant
Benedikt Kost
Genome Biology , 2001, DOI: 10.1186/gb-2001-2-8-reports4019
Abstract: Now that most of the Arabidopsis genome is sequenced, plant biologists are left with the task of assigning functions to the large number of newly identified genes. Speakers at this Royal Society Discussion Meeting presented data clarifying the cellular and developmental functions of a variety of plant genes.Mike Bevan (John Innes Centre, Norwich, UK) presented an overview of the current status of the Arabidopsis genome project. The sequence of ten contigs covering the arms of all five Arabidopsis chromosomes, as well as of a large proportion of the centromeric heterochromatin, has been determined, thoroughly annotated and organized in public databases. The sequenced part of the Arabidopsis genome contains about 25,000 predicted genes, 70% of which show significant homology to known genes of other organisms. Interestingly, the Arabidopsis genome contains many more genes than the Drosophila genome (14,000 genes), although a similar number of distinct categories of proteins are thought to be present in both organisms (11-12,000). This indicates the presence in the Arabidopsis genome of large families of genes that encode similar proteins.The challenge now confronting the plant research community, as seen by Bevan, is to generate an integrated functional map of the Arabidopsis genome or, in more popular terms, a "virtual Arabidopsis plant". He envisages the virtual plant as an extensive database that contains functional information collected under various experimental conditions for each identified gene. Information to be incorporated into this database would include description of gene-expression patterns and knockout phenotypes as well as of biochemical properties, intracellular localization and interaction partners of gene products. An organized collection of 100,000 Arabidopsis T-DNA or transposon-insertion lines, together with the sequences of the genomic regions flanking the insertion sites, is expected to be available by 2005 and will allow easy identification of
Twistor variational principle for null strings
Kost' Ilyenko
Physics , 2001, DOI: 10.1016/S0920-5632(01)01540-7
Abstract: I present a twistor action functional for null 2-surfaces (null strings) in 4D Minkowski spacetime. The proposed formulation is reparametrization invariant and free of algebraic and differential constraints. Proposed approach results in derivation of evolution equations for the null strings. It is shown that non-geodesic null strings are contained in the presented formalism. A discussion of the problem of minimality for 2-surfaces with degenerate induced metric is given. I also speculate on the possible description of strings (time-like 2-surfaces) and conventional (space-like) 2-surfaces.
E-Learning and School Development - Strengths and Challenges of Capacity Building in School Development Projects
Line Skov Hansen,Anne-Karin Sunnev?g,Anne Kost?l
International Journal of Advanced Corporate Learning (iJAC) , 2011, DOI: 10.3991/ijac.v4i3.1737
Abstract: - This paper intends to focus on the strengths and challenges of capacity building in school development projects. The paper is based on practical experiences with three different projects CLL (Classroom Management, Learning and Teaching Authority) in Norway, the implementation of the LP- (learning environment and pedagogical analysis) model in Denmark as well as professional development of school administrators in a Danish municipality. The total number of participants in these projects is approximately 500 schools and 24 000 teachers and school administrators. One of the challenges about school improvement in general, is linked to the development of competences and training of employees. Training of teachers and school administrators is often costly in terms of time, finances and organization. In accordance with these challenges, Centre of the Study of Educational Practice (SePU), Norway and Centre for Knowledge-Based Educational Practice (CVIPP), Denmark have designed projects for developing competences and training based on “blended learning” concepts. The didactic designs, in all three projects, are based on problem-oriented e-learning modules that are approached in teams. Through learning in teams, competences are developed together with colleagues. Through e-learning training and development of competences can take place at each school, within the limits and resources available at the school by using e-learning. E-learning can therefore contribute to improved flexibility in human resource development and lifelong learning.
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