T. Slivnik - Academia.edu (original) (raw)
Papers by T. Slivnik
Giant unilamellar phospholipid vesicles were prepared by the method of electroformation from 1-pa... more Giant unilamellar phospholipid vesicles were prepared by the method of electroformation from 1-palmitoyl-2-oleoyl-sn-glycero-3phosphatidylcholine (POPC). We studied the influence of different concentrations of the surfactant octaethyleneglycol dodecylether (C12E8) on the spontaneous shape transformations of POPC vesicles at room temperature. In accordance with previous results, we observed that low concentration of C 12E 8 increased the speed of the characteristic vesicle shape transformation, starting from the initial shape with thin tubular protrusion, through beaded protrusion where the number of beads gradually decreased, to final spherical shapes with invagination, whereby the average mean curvature of the vesicle membrane monotonously decreased. In contrast, higher concentration of C12E8 initially induced the shape transformation in the ‘‘opposite direction’’: in the protrusion, the number of beads gradually increased and eventually a tube was formed whereby the average mean c...
Journal of computational and applied mathematics, 1986
We consider a two-parameter weakly coupled eigenvalue problem for matrix equations. Under known a... more We consider a two-parameter weakly coupled eigenvalue problem for matrix equations. Under known assumptions [4] such a problem can be reduced to a system of one-parameter problems in a tensor product space, after which it can be treated by known numerical methods. The method is illustrated by a numerical example of the simple two-parameter problem and the example of Binding and Browne [5]. It turns out that the method is especially suitable for problems of smaller orders.
IEE Proceedings A Physical Science, Measurement and Instrumentation, Management and Education, Reviews, 1983
ABSTRACT The problem of a metallic toroid immersed in a homogeneous electric field is treated in ... more ABSTRACT The problem of a metallic toroid immersed in a homogeneous electric field is treated in the paper. The expression for the potential in the space around the toroid is given. Electric field strengths at the surface and axis of the toroid are described in terms of normalised functions. The influence of toroid dimensions on the electric field distribution is also shown.
Proceedings. 1998 IEEE International Conference on Robotics and Automation (Cat. No.98CH36146), 1998
ABSTRACT A circular robot in unknown environment, populated by non-overlapping obstacles is consi... more ABSTRACT A circular robot in unknown environment, populated by non-overlapping obstacles is considered. The robot is equipped with a discrete scanner e.g. laser range scanner. We present a method for local construction of a one-dimensional structure, similar to the generalized Voronoi diagram. We call this structure a generalized local Voronoi diagram (GLVD). GLVD is constructed from scan points of the visible region around the robot. We showed that GLVD partly matches, within the tolerances determined by the uncertainties of the scan points, the generalized Voronoi diagram generated by the free-form obstacles. The existence of a function, which groups the scan points into appropriate clusters, is required. The typical results of the experiments, conducted in the laboratory using SICK's laser range scanner PLS200, are presented
The IEEE Region 8 EUROCON 2003. Computer as a Tool., 2003
The steric effect of counterions on the electrical properties of spherical electric double layer ... more The steric effect of counterions on the electrical properties of spherical electric double layer of concave shape is discussed. In the theory, the electrostatic interaction is described by the mean field approximation, while the finite size of particles in the solution is considered by the excluded volume effect. We showed that near the spherical charged surface of concave shape, the
2005 IEEE Vehicle Power and Propulsion Conference, 2005
In order to develop an outstanding electric vehicle (EV) we have to use all the advantages which ... more In order to develop an outstanding electric vehicle (EV) we have to use all the advantages which are offered by the transition to electric propulsion system. Our concept involves direct drive (DD) propulsion system with four high specific torque inwheel electric motors, improved aerodynamics of a vehicle, weight reduction and optimized hybrid power sources involving a low power high energy
The IEEE Region 8 EUROCON 2003. Computer as a Tool., 2003
Membrane properties of giant POPC phospholipids vesicles have been studied in the past. It has be... more Membrane properties of giant POPC phospholipids vesicles have been studied in the past. It has been observed that addition of the C12E8 surfactant may increase the speed of membrane transformation, induce the formation of vesicle protrusions and reduce the lifespan of the POPC vesicles. In this paper we studied the influence of different concentrations of the C12E8 surfactant on the
[1991 Proceedings] 6th Mediterranean Electrotechnical Conference, 1991
2000 10th Mediterranean Electrotechnical Conference. Information Technology and Electrotechnology for the Mediterranean Countries. Proceedings. MeleCon 2000 (Cat. No.00CH37099), 1998
ABSTRACT Movement of the gates is an everyday task performed on a dam of hydroelectric a power st... more ABSTRACT Movement of the gates is an everyday task performed on a dam of hydroelectric a power station. This operation is often controlled remotely by measuring the positioning of the gates and a level of the current in the driving motors. This method of control cannot, however, detect anomalies, such as asymmetric movement of gates, faults in drive gearwheel etc. We therefore decided to devise a new improved system for the protection of gate movement which is described in our paper. It is based on measuring the forces applied to the transmission construction. The transducers with resistive strain gauges are mounted on the frame bearings and the strains are subsequently measured. The output signal from the transducer is proportional to a force applied to the frame. The transducers are installed at the points of the largest strain. For the protection against uneven movement of the left and right chains, the strain transmitters are inserted in the bearings of the main gearwheel, to measure the compression. The whole system is controlled by the microprocessor. The details on sensors, the electronic instrumentation needed, and the software of the controlling computer, are also described in the paper. This system has been tested, and regularly used, on the power stations of Drava river in Slovenia.
Journal of Physical Chemistry C, 2007
The transmembrane distribution of membrane constituents in the two leaflets of a cylindrical bila... more The transmembrane distribution of membrane constituents in the two leaflets of a cylindrical bilayer, which is in contact on both sides with an electrolyte solution, was studied by mathematical modeling. The model considers electrostatic interactions between the charged membrane molecules and the monovalent ions of the electrolyte solution, the bending elasticity of the membrane, as well as the anisotropy of the molecular intrinsic shape in the membrane. We showed that the strongly anisotropic uncharged membrane constituents are distributed asymmetrically between the two leaflets of the membrane. The asymmetric transmembrane distribution of charged weakly anisotropic membrane constituents is caused by the difference between the ionic strengths in the outer solutions and those in the inner solutions. For strongly anisotropic charged constituents in the membrane, we found that the asymmetric transmembrane distribution is driven by an interplay between the shape and the charge of the membrane constituents, as well as the difference between the ionic strengths in the outer solutions and those in the inner solutions. We also showed that the composition of the bilayer and the intrinsic curvatures of membrane components influence the stability of the tube.
IEEE Transactions on Systems, Man, and Cybernetics - Part A: Systems and Humans, 2000
We consider the problem of building local free space representation by a circular-base robot, ope... more We consider the problem of building local free space representation by a circular-base robot, operating in an unknown bounded planar environment populated by obstacles of arbitrary shape. In the unknown environment, the robot depends on its sensors; in our case, this is the laser range scanner. A new structure is represented, termed the generalized local Voronoi diagram (GLVD) , constructed directly from sensory data, obtained from an observation of the local environment, that is from the visible region. GLVD is obtained by deleting some edges from the ordinary Voronoi diagram, which is generated by the measured scanned points from the visible region. Crucial for the acquisition of the GLVD is the clusterization of the scanned points. Clusterization means grouping of the scanned points into distinct clusters, each having a specific property, e.g., for a particular point in the cluster, the nearest neighboring point should not lie further than a prescribed distance away. The relevant part of GLVD, the portion of GLVD which is in accordance with the generalized Voronoi diagram of the environment, is determined. Eventual differences between these two structures are discussed and experimental results are presented.
IEEE Transactions on Biomedical Engineering, 2002
Using finite-element method (FEM) effective conductivity of cell suspension was calculated for di... more Using finite-element method (FEM) effective conductivity of cell suspension was calculated for different cell volume fractions and membrane conductivities. Cells were modeled as spheres having equivalent conductivity and were organized in cubic lattices, layers and clusters. The results were compared to different analytical expressions for effective conductivity and they showed that Maxwell theory is valid also for higher volume fractions.
Engineering Structures, 1997
The problem of the optimal cut of belts into pieces of given dimensions is resolved using dynamic... more The problem of the optimal cut of belts into pieces of given dimensions is resolved using dynamic programming and the genetic algorithm. When using dynamic programming, our basic problem is how to fill the knapsack in the optimal way. We use the solution to this problem to design an algorithm for the optimal cut of the belts into pieces. This problem is also dealt with by applying the genetic algorithm. The dynamic programming and genetic algorithm, the two methods of solving the problem of the optimal cut of belts, are compared and their space and time requirements are determined. © 1997 Elsevier Science Ltd.
Computer Communications, 2003
This paper analyses and compares the performance of forward planning conflict-free (FPCF), virtua... more This paper analyses and compares the performance of forward planning conflict-free (FPCF), virtual output queuing-partitioned (VOQ-P) and virtual output queuing-shared (VOQ-S) packet switches. The influence of packet burst size, offered switch load and packet switch size are all investigated. Packet loss probability, average packet delay and 99.9% packet delay values are also derived. In comparison tests, FPCF packet switches perform better than VOQ-P packet switches and yield similar results to VOQ-S packet switches. The advantage of VOQ-S switches is manifested in somewhat lower probability of packet loss, while the advantage of FPCF switches is revealed in the limited values of their maximum packet delays. q
fs.cvut.cz
... Project description: Fig.1 - Visualisation of the lower leg and contact stress distribution a... more ... Project description: Fig.1 - Visualisation of the lower leg and contact stress distribution acting on the acetabular cartilage. Fig.2 - Peak contact stress in the dysplastic human hips during downstairs walking. ... Researchers: RNDr. Matej Daniel, Ph.D., prof. dr. Ale Iglič, prof. dr. ...
Bioelectrochemistry, 2004
Giant unilamellar phospholipid vesicles were prepared by the method of electroformation from 1-pa... more Giant unilamellar phospholipid vesicles were prepared by the method of electroformation from 1-palmitoyl-2-oleoyl-sn-glycero-3phosphatidylcholine (POPC). We studied the influence of different concentrations of the surfactant octaethyleneglycol dodecylether (C 12 E 8 ) on the spontaneous shape transformations of POPC vesicles at room temperature. In accordance with previous results, we observed that low concentration of C 12 E 8 increased the speed of the characteristic vesicle shape transformation, starting from the initial shape with thin tubular protrusion, through beaded protrusion where the number of beads gradually decreased, to final spherical shapes with invagination, whereby the average mean curvature of the vesicle membrane monotonously decreased. In contrast, higher concentration of C 12 E 8 initially induced the shape transformation in the ''opposite direction'': in the protrusion, the number of beads gradually increased and eventually a tube was formed whereby the average mean curvature of the vesicle membrane gradually increased. However, at a certain point, an abrupt shape change took place to yield the vesicle with invagination. In this transition, the average mean curvature of the vesicle membrane discontinuously decreased. After this transition, the vesicle began to shrink and finally disappeared. We discuss possible mechanisms involved in the observed transformations. D
Advances in Planar Lipid Bilayers and Liposomes, 2008
ABSTRACT
International Journal of Nanomedicine, 2011
Giant unilamellar phospholipid vesicles were prepared by the method of electroformation from 1-pa... more Giant unilamellar phospholipid vesicles were prepared by the method of electroformation from 1-palmitoyl-2-oleoyl-sn-glycero-3phosphatidylcholine (POPC). We studied the influence of different concentrations of the surfactant octaethyleneglycol dodecylether (C12E8) on the spontaneous shape transformations of POPC vesicles at room temperature. In accordance with previous results, we observed that low concentration of C 12E 8 increased the speed of the characteristic vesicle shape transformation, starting from the initial shape with thin tubular protrusion, through beaded protrusion where the number of beads gradually decreased, to final spherical shapes with invagination, whereby the average mean curvature of the vesicle membrane monotonously decreased. In contrast, higher concentration of C12E8 initially induced the shape transformation in the ‘‘opposite direction’’: in the protrusion, the number of beads gradually increased and eventually a tube was formed whereby the average mean c...
Journal of computational and applied mathematics, 1986
We consider a two-parameter weakly coupled eigenvalue problem for matrix equations. Under known a... more We consider a two-parameter weakly coupled eigenvalue problem for matrix equations. Under known assumptions [4] such a problem can be reduced to a system of one-parameter problems in a tensor product space, after which it can be treated by known numerical methods. The method is illustrated by a numerical example of the simple two-parameter problem and the example of Binding and Browne [5]. It turns out that the method is especially suitable for problems of smaller orders.
IEE Proceedings A Physical Science, Measurement and Instrumentation, Management and Education, Reviews, 1983
ABSTRACT The problem of a metallic toroid immersed in a homogeneous electric field is treated in ... more ABSTRACT The problem of a metallic toroid immersed in a homogeneous electric field is treated in the paper. The expression for the potential in the space around the toroid is given. Electric field strengths at the surface and axis of the toroid are described in terms of normalised functions. The influence of toroid dimensions on the electric field distribution is also shown.
Proceedings. 1998 IEEE International Conference on Robotics and Automation (Cat. No.98CH36146), 1998
ABSTRACT A circular robot in unknown environment, populated by non-overlapping obstacles is consi... more ABSTRACT A circular robot in unknown environment, populated by non-overlapping obstacles is considered. The robot is equipped with a discrete scanner e.g. laser range scanner. We present a method for local construction of a one-dimensional structure, similar to the generalized Voronoi diagram. We call this structure a generalized local Voronoi diagram (GLVD). GLVD is constructed from scan points of the visible region around the robot. We showed that GLVD partly matches, within the tolerances determined by the uncertainties of the scan points, the generalized Voronoi diagram generated by the free-form obstacles. The existence of a function, which groups the scan points into appropriate clusters, is required. The typical results of the experiments, conducted in the laboratory using SICK's laser range scanner PLS200, are presented
The IEEE Region 8 EUROCON 2003. Computer as a Tool., 2003
The steric effect of counterions on the electrical properties of spherical electric double layer ... more The steric effect of counterions on the electrical properties of spherical electric double layer of concave shape is discussed. In the theory, the electrostatic interaction is described by the mean field approximation, while the finite size of particles in the solution is considered by the excluded volume effect. We showed that near the spherical charged surface of concave shape, the
2005 IEEE Vehicle Power and Propulsion Conference, 2005
In order to develop an outstanding electric vehicle (EV) we have to use all the advantages which ... more In order to develop an outstanding electric vehicle (EV) we have to use all the advantages which are offered by the transition to electric propulsion system. Our concept involves direct drive (DD) propulsion system with four high specific torque inwheel electric motors, improved aerodynamics of a vehicle, weight reduction and optimized hybrid power sources involving a low power high energy
The IEEE Region 8 EUROCON 2003. Computer as a Tool., 2003
Membrane properties of giant POPC phospholipids vesicles have been studied in the past. It has be... more Membrane properties of giant POPC phospholipids vesicles have been studied in the past. It has been observed that addition of the C12E8 surfactant may increase the speed of membrane transformation, induce the formation of vesicle protrusions and reduce the lifespan of the POPC vesicles. In this paper we studied the influence of different concentrations of the C12E8 surfactant on the
[1991 Proceedings] 6th Mediterranean Electrotechnical Conference, 1991
2000 10th Mediterranean Electrotechnical Conference. Information Technology and Electrotechnology for the Mediterranean Countries. Proceedings. MeleCon 2000 (Cat. No.00CH37099), 1998
ABSTRACT Movement of the gates is an everyday task performed on a dam of hydroelectric a power st... more ABSTRACT Movement of the gates is an everyday task performed on a dam of hydroelectric a power station. This operation is often controlled remotely by measuring the positioning of the gates and a level of the current in the driving motors. This method of control cannot, however, detect anomalies, such as asymmetric movement of gates, faults in drive gearwheel etc. We therefore decided to devise a new improved system for the protection of gate movement which is described in our paper. It is based on measuring the forces applied to the transmission construction. The transducers with resistive strain gauges are mounted on the frame bearings and the strains are subsequently measured. The output signal from the transducer is proportional to a force applied to the frame. The transducers are installed at the points of the largest strain. For the protection against uneven movement of the left and right chains, the strain transmitters are inserted in the bearings of the main gearwheel, to measure the compression. The whole system is controlled by the microprocessor. The details on sensors, the electronic instrumentation needed, and the software of the controlling computer, are also described in the paper. This system has been tested, and regularly used, on the power stations of Drava river in Slovenia.
Journal of Physical Chemistry C, 2007
The transmembrane distribution of membrane constituents in the two leaflets of a cylindrical bila... more The transmembrane distribution of membrane constituents in the two leaflets of a cylindrical bilayer, which is in contact on both sides with an electrolyte solution, was studied by mathematical modeling. The model considers electrostatic interactions between the charged membrane molecules and the monovalent ions of the electrolyte solution, the bending elasticity of the membrane, as well as the anisotropy of the molecular intrinsic shape in the membrane. We showed that the strongly anisotropic uncharged membrane constituents are distributed asymmetrically between the two leaflets of the membrane. The asymmetric transmembrane distribution of charged weakly anisotropic membrane constituents is caused by the difference between the ionic strengths in the outer solutions and those in the inner solutions. For strongly anisotropic charged constituents in the membrane, we found that the asymmetric transmembrane distribution is driven by an interplay between the shape and the charge of the membrane constituents, as well as the difference between the ionic strengths in the outer solutions and those in the inner solutions. We also showed that the composition of the bilayer and the intrinsic curvatures of membrane components influence the stability of the tube.
IEEE Transactions on Systems, Man, and Cybernetics - Part A: Systems and Humans, 2000
We consider the problem of building local free space representation by a circular-base robot, ope... more We consider the problem of building local free space representation by a circular-base robot, operating in an unknown bounded planar environment populated by obstacles of arbitrary shape. In the unknown environment, the robot depends on its sensors; in our case, this is the laser range scanner. A new structure is represented, termed the generalized local Voronoi diagram (GLVD) , constructed directly from sensory data, obtained from an observation of the local environment, that is from the visible region. GLVD is obtained by deleting some edges from the ordinary Voronoi diagram, which is generated by the measured scanned points from the visible region. Crucial for the acquisition of the GLVD is the clusterization of the scanned points. Clusterization means grouping of the scanned points into distinct clusters, each having a specific property, e.g., for a particular point in the cluster, the nearest neighboring point should not lie further than a prescribed distance away. The relevant part of GLVD, the portion of GLVD which is in accordance with the generalized Voronoi diagram of the environment, is determined. Eventual differences between these two structures are discussed and experimental results are presented.
IEEE Transactions on Biomedical Engineering, 2002
Using finite-element method (FEM) effective conductivity of cell suspension was calculated for di... more Using finite-element method (FEM) effective conductivity of cell suspension was calculated for different cell volume fractions and membrane conductivities. Cells were modeled as spheres having equivalent conductivity and were organized in cubic lattices, layers and clusters. The results were compared to different analytical expressions for effective conductivity and they showed that Maxwell theory is valid also for higher volume fractions.
Engineering Structures, 1997
The problem of the optimal cut of belts into pieces of given dimensions is resolved using dynamic... more The problem of the optimal cut of belts into pieces of given dimensions is resolved using dynamic programming and the genetic algorithm. When using dynamic programming, our basic problem is how to fill the knapsack in the optimal way. We use the solution to this problem to design an algorithm for the optimal cut of the belts into pieces. This problem is also dealt with by applying the genetic algorithm. The dynamic programming and genetic algorithm, the two methods of solving the problem of the optimal cut of belts, are compared and their space and time requirements are determined. © 1997 Elsevier Science Ltd.
Computer Communications, 2003
This paper analyses and compares the performance of forward planning conflict-free (FPCF), virtua... more This paper analyses and compares the performance of forward planning conflict-free (FPCF), virtual output queuing-partitioned (VOQ-P) and virtual output queuing-shared (VOQ-S) packet switches. The influence of packet burst size, offered switch load and packet switch size are all investigated. Packet loss probability, average packet delay and 99.9% packet delay values are also derived. In comparison tests, FPCF packet switches perform better than VOQ-P packet switches and yield similar results to VOQ-S packet switches. The advantage of VOQ-S switches is manifested in somewhat lower probability of packet loss, while the advantage of FPCF switches is revealed in the limited values of their maximum packet delays. q
fs.cvut.cz
... Project description: Fig.1 - Visualisation of the lower leg and contact stress distribution a... more ... Project description: Fig.1 - Visualisation of the lower leg and contact stress distribution acting on the acetabular cartilage. Fig.2 - Peak contact stress in the dysplastic human hips during downstairs walking. ... Researchers: RNDr. Matej Daniel, Ph.D., prof. dr. Ale Iglič, prof. dr. ...
Bioelectrochemistry, 2004
Giant unilamellar phospholipid vesicles were prepared by the method of electroformation from 1-pa... more Giant unilamellar phospholipid vesicles were prepared by the method of electroformation from 1-palmitoyl-2-oleoyl-sn-glycero-3phosphatidylcholine (POPC). We studied the influence of different concentrations of the surfactant octaethyleneglycol dodecylether (C 12 E 8 ) on the spontaneous shape transformations of POPC vesicles at room temperature. In accordance with previous results, we observed that low concentration of C 12 E 8 increased the speed of the characteristic vesicle shape transformation, starting from the initial shape with thin tubular protrusion, through beaded protrusion where the number of beads gradually decreased, to final spherical shapes with invagination, whereby the average mean curvature of the vesicle membrane monotonously decreased. In contrast, higher concentration of C 12 E 8 initially induced the shape transformation in the ''opposite direction'': in the protrusion, the number of beads gradually increased and eventually a tube was formed whereby the average mean curvature of the vesicle membrane gradually increased. However, at a certain point, an abrupt shape change took place to yield the vesicle with invagination. In this transition, the average mean curvature of the vesicle membrane discontinuously decreased. After this transition, the vesicle began to shrink and finally disappeared. We discuss possible mechanisms involved in the observed transformations. D
Advances in Planar Lipid Bilayers and Liposomes, 2008
ABSTRACT
International Journal of Nanomedicine, 2011