V. Eidukynas | Kaunas University of Technology (original) (raw)

Papers by V. Eidukynas

Nuclear Engineering and Design

Journal of Vibroengineering

The influence of swinging leg on long jump result is analyzed in the paper. For this purpose thre... more The influence of swinging leg on long jump result is analyzed in the paper. For this purpose three mass link-age type model is constructed the mobility of foot joint is evaluated in which. After natural frequencies determina-tion mass centre coordinates of the separate body parts, their derivatives of the first order and the coordinates of general mass centre are expressed. The equation of kinetic moment the first order derivative in time of which is the searched driving moment is obtained.

The investigation was performed with purpose to establish correlation between drivers pose and in... more The investigation was performed with purpose to establish correlation between drivers pose and interverteb-ral forces in junction of thoracic and lumbar spinal curves with vertical direction kinematical upward impact. An mo-del created for analyzis, it consist of manikin and envin-ronment. Between manikins vertebras are placed contact elements which monitor intervertebral force changes. Du-ring simuliation there was changed manikins hip and knee settings and monitored changes of intervertebral forces. According stated rezults of this investigation, there was established driver pose with lowest intervertebral force values.

This paper discusses the methods of fastening a cl avicle reinforcement plate to the bone. In ord... more This paper discusses the methods of fastening a cl avicle reinforcement plate to the bone. In order to identify the advantages and disad vantages of different types of plates, computer modeling and strength analysis was perform ed for two plates, which were manufactured from different materials and which emp loyed different mounting design elements.

Human spine is a complex structure, the which main function of which is to protect spinal cord an... more Human spine is a complex structure, the which main function of which is to protect spinal cord and to transfer loads from head through trunk till pelvis. Spine consist of 24 stiff vertebrae, connected by intervertebral discs, allowing slight movement of the vertebrae due to elastic deformation of the discs, thus giving a flexibility to the whole spine. The pressure acting the intervertebral joint disc is about 10 N/cm 2

International Journal of Computing, 2014

Performance comparison of conventional and spread spectrum signals in Time of Flight estimation i... more Performance comparison of conventional and spread spectrum signals in Time of Flight estimation is given. Ultrasonic measurement under multiple reflections condition is analyzed. It was indicated that if two reflections are in close proximity the neighboring signal induces energy leak into its opponent signal. Due to such situation ToF estimate is obtained with bias error. Narrow signals like single rectangular pulse, should suffer less from the aforementioned phenomena. But use of spread spectrum signals is preferred thanks to their compressibility. It was hypothesized that such long signals will have worse bias error due to neighbor reflection. Goal of the investigation was to compare the performance in multiple reflections environment in Time of Flight estimation for classical signals and spread spectrum signals. Investigation revealed that spread spectrum signals have better performance in a sense of bias error caused by neighboring reflection.

For representatives of sport games are very important components of physical abilities – spring a... more For representatives of sport games are very important components of physical abilities – spring and rate of psychomotoric reaction. For the following sportsman’s especially important is the rate of psychomotoric reaction, which defines reaction to the constantly changing ambience, similar to the sport action. Testing system, which simulates the situation of sports game, was created in the department of Informatics and biomechanics of LKKA. This system allows estimating the physical capabilities of player – spring and the speed of psychomotoric reaction. The speed of psychomotoric reaction is evaluated by making the jump-up. The influence of the height of jump-up on the spring and speed of reaction of sportsman is investigated. Considering the results of experiments and statistical analysis some recommendations are given and conclusions withdrawn.

Sensor Letters, 2014

Resolution and signal-to-noise ratio performance improvement of ultrasound applications in measur... more Resolution and signal-to-noise ratio performance improvement of ultrasound applications in measurement or imaging demands both high energy and wideband signals for excitation. Conventional signals like pulse and toneburst do not satisfy both requirements, but spread spectrum signals are capable to increase the signal energy and maintain the resolution. We suggest using novel spread spectrum signals generation technique: trains of arbitrary width and position pulses. We hypothesize that such signals should have properties of chirp and of a single pulse. Dedicated acquisition system is needed in order to carry out the investigation of such signals. The design of such system is presented. The system is capable of generation and reception of the arbitrary width and position and conventional pulse signals. The structure of the system is also presented. It consists of transducer positioning unit, specialized pulser, receiver and analog-to-digital conversion. The investigation of the system performance is presented. Study revealed that both pulser and preamplifier can be used for 0.5 MHz to 30 MHz frequency range. Excitation signal amplitude can reach 200 V for unipolar signals and 400 Vp-p for bipolar signals. Variation of pulser output impedance measured according to modified procedure described in EN 12668-1 standard is within 7  to 21  range. Recovery time according to EN 12668-1 standard is 2 s.

Mechanika, 2012

ABSTRACT In this article the thermodynamical and mechanical research of organic thermal insulatio... more ABSTRACT In this article the thermodynamical and mechanical research of organic thermal insulation slabs prepared from cardboard refuse and synthetical binding material is presented. For this aim the samples with different amount of binding material, different density and different thermal insulation material granulometry were used. During the research it was established that granulometric composition of thermal insulation material and amount of the binder influence density of the samples. In all cases density influences the alternation of thermal conduction coefficient. The lowest thermal conduction have the samples prepared from milled cardboard, bolted through 1.5 mm bolter. During the research of mechanical characteristics it was determined that the best strength characteristics have the samples prepared with bigger amount of the binder and higher density.

A new method based on Ping He's technique for simultaneous measurement of frequency dependant thi... more A new method based on Ping He's technique for simultaneous measurement of frequency dependant thickness and attenuation was developed without any need of a priori knowledge of the material parameters. The thickness and attenuation coefficient for longitudinal wave were measured in a thin specimen of glass fiber reinforced plastic produced by Resin Transfer Molding. A 5 MHz pulse of 0.1 µs duration was used as excitation signal. Mean error and standard deviation of the frequency dependant thickness are used to compare both techniques. The new method has demonstrated to be more accurate than conventional Ping He's technique, and can be implemented automatically thus saving processing time and increasing accuracy. Measurement of the attenuation coefficient is achieved using the frequency dependent thickness without requiring any additional parameter of the material.

Nuclear Engineering and Design

Journal of Vibroengineering

The influence of swinging leg on long jump result is analyzed in the paper. For this purpose thre... more The influence of swinging leg on long jump result is analyzed in the paper. For this purpose three mass link-age type model is constructed the mobility of foot joint is evaluated in which. After natural frequencies determina-tion mass centre coordinates of the separate body parts, their derivatives of the first order and the coordinates of general mass centre are expressed. The equation of kinetic moment the first order derivative in time of which is the searched driving moment is obtained.

The investigation was performed with purpose to establish correlation between drivers pose and in... more The investigation was performed with purpose to establish correlation between drivers pose and interverteb-ral forces in junction of thoracic and lumbar spinal curves with vertical direction kinematical upward impact. An mo-del created for analyzis, it consist of manikin and envin-ronment. Between manikins vertebras are placed contact elements which monitor intervertebral force changes. Du-ring simuliation there was changed manikins hip and knee settings and monitored changes of intervertebral forces. According stated rezults of this investigation, there was established driver pose with lowest intervertebral force values.

This paper discusses the methods of fastening a cl avicle reinforcement plate to the bone. In ord... more This paper discusses the methods of fastening a cl avicle reinforcement plate to the bone. In order to identify the advantages and disad vantages of different types of plates, computer modeling and strength analysis was perform ed for two plates, which were manufactured from different materials and which emp loyed different mounting design elements.

Human spine is a complex structure, the which main function of which is to protect spinal cord an... more Human spine is a complex structure, the which main function of which is to protect spinal cord and to transfer loads from head through trunk till pelvis. Spine consist of 24 stiff vertebrae, connected by intervertebral discs, allowing slight movement of the vertebrae due to elastic deformation of the discs, thus giving a flexibility to the whole spine. The pressure acting the intervertebral joint disc is about 10 N/cm 2

International Journal of Computing, 2014

Performance comparison of conventional and spread spectrum signals in Time of Flight estimation i... more Performance comparison of conventional and spread spectrum signals in Time of Flight estimation is given. Ultrasonic measurement under multiple reflections condition is analyzed. It was indicated that if two reflections are in close proximity the neighboring signal induces energy leak into its opponent signal. Due to such situation ToF estimate is obtained with bias error. Narrow signals like single rectangular pulse, should suffer less from the aforementioned phenomena. But use of spread spectrum signals is preferred thanks to their compressibility. It was hypothesized that such long signals will have worse bias error due to neighbor reflection. Goal of the investigation was to compare the performance in multiple reflections environment in Time of Flight estimation for classical signals and spread spectrum signals. Investigation revealed that spread spectrum signals have better performance in a sense of bias error caused by neighboring reflection.

For representatives of sport games are very important components of physical abilities – spring a... more For representatives of sport games are very important components of physical abilities – spring and rate of psychomotoric reaction. For the following sportsman’s especially important is the rate of psychomotoric reaction, which defines reaction to the constantly changing ambience, similar to the sport action. Testing system, which simulates the situation of sports game, was created in the department of Informatics and biomechanics of LKKA. This system allows estimating the physical capabilities of player – spring and the speed of psychomotoric reaction. The speed of psychomotoric reaction is evaluated by making the jump-up. The influence of the height of jump-up on the spring and speed of reaction of sportsman is investigated. Considering the results of experiments and statistical analysis some recommendations are given and conclusions withdrawn.

Sensor Letters, 2014

Resolution and signal-to-noise ratio performance improvement of ultrasound applications in measur... more Resolution and signal-to-noise ratio performance improvement of ultrasound applications in measurement or imaging demands both high energy and wideband signals for excitation. Conventional signals like pulse and toneburst do not satisfy both requirements, but spread spectrum signals are capable to increase the signal energy and maintain the resolution. We suggest using novel spread spectrum signals generation technique: trains of arbitrary width and position pulses. We hypothesize that such signals should have properties of chirp and of a single pulse. Dedicated acquisition system is needed in order to carry out the investigation of such signals. The design of such system is presented. The system is capable of generation and reception of the arbitrary width and position and conventional pulse signals. The structure of the system is also presented. It consists of transducer positioning unit, specialized pulser, receiver and analog-to-digital conversion. The investigation of the system performance is presented. Study revealed that both pulser and preamplifier can be used for 0.5 MHz to 30 MHz frequency range. Excitation signal amplitude can reach 200 V for unipolar signals and 400 Vp-p for bipolar signals. Variation of pulser output impedance measured according to modified procedure described in EN 12668-1 standard is within 7  to 21  range. Recovery time according to EN 12668-1 standard is 2 s.

Mechanika, 2012

ABSTRACT In this article the thermodynamical and mechanical research of organic thermal insulatio... more ABSTRACT In this article the thermodynamical and mechanical research of organic thermal insulation slabs prepared from cardboard refuse and synthetical binding material is presented. For this aim the samples with different amount of binding material, different density and different thermal insulation material granulometry were used. During the research it was established that granulometric composition of thermal insulation material and amount of the binder influence density of the samples. In all cases density influences the alternation of thermal conduction coefficient. The lowest thermal conduction have the samples prepared from milled cardboard, bolted through 1.5 mm bolter. During the research of mechanical characteristics it was determined that the best strength characteristics have the samples prepared with bigger amount of the binder and higher density.

A new method based on Ping He's technique for simultaneous measurement of frequency dependant thi... more A new method based on Ping He's technique for simultaneous measurement of frequency dependant thickness and attenuation was developed without any need of a priori knowledge of the material parameters. The thickness and attenuation coefficient for longitudinal wave were measured in a thin specimen of glass fiber reinforced plastic produced by Resin Transfer Molding. A 5 MHz pulse of 0.1 µs duration was used as excitation signal. Mean error and standard deviation of the frequency dependant thickness are used to compare both techniques. The new method has demonstrated to be more accurate than conventional Ping He's technique, and can be implemented automatically thus saving processing time and increasing accuracy. Measurement of the attenuation coefficient is achieved using the frequency dependent thickness without requiring any additional parameter of the material.