Search results for "Jump"
showing 10 items of 401 documents
H∞ control for two-dimensional Markovian jump systems with state-delays and defective mode information
2013
This paper investigates the problem ofℋ∞state-feedback control for a class of two-dimensional (2D) discrete-time Markovian jump linear time-delay systems with defective mode information. The mathematical model of the 2D system is established based on the well-known Fornasini-Marchesini local state-space model, and the defective mode information simultaneously consists of the exactly known, partially unknown, and uncertain transition probabilities. By carefully analyzing the features of the transition probability matrices, together with the convexification of uncertain domains, a newℋ∞performance analysis criterion for the underlying system is firstly derived, and then theℋ∞state-feedback co…
Validation of a subject specific 3-actuator torque-driven model in human vertical jumping.
2013
In this study, a forward dynamic subject specific 3-actuator torque-driven model of the human musculoskeletal system was created based on measurements of individual characteristics of a subject. Simulation results were compared with experimental vertical squat jumping with and without adding weights. By analyzing kinematic and kinetic experimental data at the instant of the toe-off for the same initial conditions, it was shown that a simple computer simulation using a suitable cost function could reproduce the real task performed by humans. This investigation is the first step in a wider project that will incorporate elastic components, and that will evaluate the advantages of the individua…
Real-time 3D imaging of Haines jumps in porous media flow.
2013
Newly developed high-speed, synchrotron-based X-ray computed microtomography enabled us to directly image pore-scale displacement events in porous rock in real time. Common approaches to modeling macroscopic fluid behavior are phenomenological, have many shortcomings, and lack consistent links to elementary pore-scale displacement processes, such as Haines jumps and snap-off. Unlike the common singular pore jump paradigm based on observations of restricted artificial capillaries, we found that Haines jumps typically cascade through 10–20 geometrically defined pores per event, accounting for 64% of the energy dissipation. Real-time imaging provided a more detailed fundamental understanding o…
New Expression of the Hydraulic Jump Roller Length
2012
AbstractThis paper presents the results of an experimental investigation on the roller length of both classical and B-jumps on smooth beds. Using the measurements conducted in this investigation and those available in the literature, a new relationship is proposed for estimating the roller length of classical and B-jumps on smooth beds. Finally, it is demonstrated that the proposed equation is also applicable to estimate the roller length of hydraulic jumps on rough horizontal beds.
New Solution of Classical Hydraulic Jump
2009
This technical note, applying dimensional analysis and incomplete self-similarity, proposes a new functional relationship for the sequent depth ratio for hydraulic jumps over both smooth and rough horizontal beds. For the smooth bed condition, experimental measurements in the literature were used to calibrate the new relationship. For the rough bed condition the data of a previous investigation were used with new measurements carried out in a rectangular horizontal flume having a gravel bed. Finally, a generalized solution of the sequent depth ratio is proposed.
Kinetics and Muscular Function in Ski Jumping
2010
Hydraulic jumps on rough beds
2007
This paper presents the results of an experimental investigation on the hydraulic jump on horizontal rough beds. Experiments were carried out to study the effect of bed roughness on both the sequent depth ratio and the roller length. The investigation allowed the writers to positively test the reliability of a new solution of the momentum equation for the sequent depth ratio as a function of the Froude number and the ratio between the roughness height and the upstream supercritical flow depth. The applicability of some empirical relationships for estimating the roller length was also tested.
Validation of portable 2D force binding systems for cross-country skiing
2013
The aim of the present study was to design, construct and scientifically validate a two-dimensional force measurement binding system for cross-country skiing. The system consists of two force measurement bindings. One binding was designed for analysing classic skiing (vertical and anterior–posterior [along the ski] force components) and the other one for skate (freestyle) skiing (vertical and medio-lateral [transverse to the ski] force components). Validation was accomplished using a three-step process: (1) accuracy tests for the sensors in two temperatures, (2) sport-specific imitation jump test on standard force plates in a laboratory and (3) comparing the system against force measurement…
Subsecond pore‐scale displacement processes and relaxation dynamics in multiphase flow
2014
With recent advances at X‐ray microcomputed tomography (μCT) synchrotron beam lines, it is now possible to study pore‐scale flow in porous rock under dynamic flow conditions. The collection of four‐dimensional data allows for the direct 3‐D visualization of fluid‐fluid displacement in porous rock as a function of time. However, even state‐of‐the‐art fast‐μCT scans require between one and a few seconds to complete and the much faster fluid movement occurring during that time interval is manifested as imaging artifacts in the reconstructed 3‐D volume. We present an approach to analyze the 2‐D radiograph data collected during fast‐μCT to study the pore‐scale displacement dynamics on the time s…
Blokķēdes tehnoloģija, tās pielietojums un potenciāls
2018
Darba mērķis ir blokķēdes tehnoloģijas un tās potenciālo pielietojuma iespēju izpēte. Darba ietvaros tika veikta blokķēdes tehnoloģijas un šajā sfērā esošo vadošo tehnoloģisko risinājumu apskate, eksistējošo tehnoloģijas ierobežojumu un iespēju analīze. Papildus tika veikta padziļinātāka Ethereum blokķēdes platformas apskate, jo pēc veiktās izpētes, tā tika izvirzīts par mūsdienu blokķēdes sfērā esošo tehnoloģisko līderi. Pēc iegūto izpētes rezultātu analīzes darba praktiskajā daļā tika veikta uz Ethereum balstītas decentralizētas lietojumprogrammas prototipa un tā pamatā esošā viedā līguma izstrāde, kas tehniski veic automatizētu auto stāvlaukumu nomas realizāciju.