SUMMARY This paper proposes a bilateral control structure with a realization of the force derivative in the control loop. Due to the inherent noisy nature of the force signal, most teleoperation schemes can make use of only a proportional (P) control structure in the force channel of the bilateral controllers. In the proposed scheme, an α–β–γ filter is designed to smoothly differentiate the force signal obtained from a reaction force observer integrated to both of the master and slave plants. The differentiated force signal is then used in a proportional-derivative (PD) force controller working together with a disturbance observer. In order to design the overall bilateral controller, an environment model based on pure spring structure is assumed. The controller is designed to enforce an exponentially decaying tracking error for both position and force signals. With the presented controller design approach, one can independently tune the controller gains of the force and the position control channels. The proposed approach is experimentally tested in a platform consisted of direct drive linear motors. As illustrated by the experiment results, the contribution of the PD control in the force channel improves the teleoperation performance especially under hard-contact motion scenarios by attenuating the oscillations, hence, improving the transparency when compared to the structures using only a P force control.
S U M M A R Y Inversion of surface wave data for crustal and upper-mantle structure is a staple of passive seismology, particularly since the advent of techniques enabling surface wave dispersion (SWD) and Rayleigh wave ellipticity measurements from ambient noise. Recent development and application of transdimensional Bayesian (TB) seismic inversion offers an approach to quantify model parameter uncertainties and trade-offs with fewer assumptions than traditional methods. Using synthetic tests, we investigate choices in the implementation of TB for the inversion of SWD and Rayleigh wave ellipticity to constrain the structure of Earth’s continental lithosphere. We focus on three aspects of the inversion: limitation of data sensitivity, assumed scaling among parameters (compressional wave speed, Vp, shear wave speed, Vs, density and radial anisotropy) and parametrization choices. We show that while surface wave data provide relatively strong constraints on the posterior distribution of Vs and, to a lesser extent, Vp, common parametrization choices can potentially bias structure estimates. This is particularly the case for radial anisotropy (ξ ), due to the inability to distinguish variations of Vp and density from those of ξ . Inferred results therefore depend substantially on the parametrization and scaling choices. We illustrate how layered parametrizations can, in the TB framework, recover smoothly varying profiles, and quantify the number of layers recoverable at different levels of measurement uncertainty. Finally, we propose two types of model parametrization for TB inversion involving multiple types of parameters. We demonstrate that by implementing an independent parametrization for different physical quantities, we can avoid imposing identical model geometry across multiple types of model parameters, and obtain better model estimates with reduced trade-offs. We advocate for such a parametrization in TB inversion of radial anisotropy using surface wave data, and when targeting disparate Vp and Vs structures such as those associated with α-β quartz transtion.
A review is presented of the rescattering plateau in laser-induced above-threshold ionization and its various features as they were discovered over time. Several theoretical explanations are discussed, from simple momentum conservation to the quantum-mechanical improved strong-field approximation and the inherent quantum orbits or, alternatively, entirely classical methods. Applications of the plateau to the extraction of atomic or molecular potentials and to the characterization of the driving laser pulse are also surveyed.
Upotreba sobnog bilja potječe još iz davne povijesti čovječanstva. Većina sobnog bilja koja se koristi u ukrašavanju interijera dolazi iz tropskih i suptropskih područja, dok ih manji broj dolazi iz umjerene klime. Prilikom odabira biljke za ukrašavanje interijera, važno je imati na umu da neke biljke nisu uvijek „moderne“ te također da ljudi imaju različita mišljenja vezano uz takav odabir. Cilj ovog rada je odrediti odgovarajuće sobno bilje za interijer jedne institucije visokog obrazovanja te utvrditi cjelokupni vizualni dojam (vizualni „geštalt“) putem ankete vezane uz određene odabrane lončanice u interijeru prostorija Veleučilišta „Marko Marulić“ u Kninu. Istraživanje je provedeno putem ankete tijekom studenog i prosinca 2014. godine na uzorku od 43 ispitanika (studenata i zaposlenika). Ustanovljeno je da su različite palme i lončanice dobile najbolje ocjene i najbolje su prihvaćene za upotrebu u interijeru Veleučilišta.
Transforming the latent value of big data into real value requires the great human intelligence and application of human-data scientists. Data scientists are expected to have a wide range of technical skills alongside being passionate self-directed people who are able to work easily with others and deliver high quality outputs under pressure. There are hundreds of university, commercial, and online courses in data science and related topics. Apart from people with breadth and depth of knowledge and experience in data science, we identify a new educational path to train "bridge persons" who combine knowledge of an organization's business with sufficient knowledge and understanding of data science to "bridge" between non-technical people in the business with highly skilled data scientists who add value to the business. The increasing proliferation of big data and the great advances made in data science do not herald in an era where all problems can be solved by deep learning and artificial intelligence. Although data science opens up many commercial and social opportunities, data science must complement other science in the search for new theory and methods to understand and manage our complex world.
Vertex-frequency analysis of graph signals is a challenging topic for research and applications. Counterparts of the short-time Fourier transform, the wavelet transform, and the Rihaczek distribution have recently been introduced to the graph-signal analysis. In this letter, we have extended the energy distributions to a general reduced interference distributions class. It can improve the vertex-frequency representation of a graph signal while preserving the marginal properties. This class is related to the spectrogram of graph signals as well. Efficiency of the proposed representations is illustrated in examples.
Research is spent on 50 respondents divided in two groups, of wich first group was combined by 25 swimmers and second group was combined by 25 water polo players from water polo club „Dabar“ from Sarajevo, at age of 12-14 years. The main goal of research was to spot the differences between speed in swimming craul technique disciplines of 25m, 50m and 100m between swimmers and water polo players of water polo club „Dabar“ from Sarajevo. It is analyzed the time swimmers will swimm craul techinuque every discipline separately: 25m (BK 25M), 50m (BK 50M) and 100m (BK 100M). For establishment of differences in speed swimming craul technique on 25m, 50m and 100m between swimmers and water polo players we used T-test analise of results for independent samples. Based on T-test analise of results for independent samples we can conclude that there is statisticly big difference between swimmer and water polo players in speed during swimming all three criterion variables (BK 25M), (BK 50M),(BK 100M).
The research was conducted on a sample of 166 students of „Secondary Technical School Travnik”, first and second malegrade who regularly attended elementary education during the 2016/2017 school year. A total of 15 variables were used in the research to assess the level of motor skills (three variables for assessing the motor skills of basketball, volleyball, handball, volleyball and athletics).The main aim of the research was to determine the quantitative changes of the motor skills of secondary school students through the longitudinal study in one school year duration under the influence of the program contents of regular physical education. Quantitative changes in motor skills and analysis of differences between initial and final measurements were determined by analysis of changes under the difference model and SSDIF analysis (Bonacin, 2004). By projecting measurement data, a hypothetical measurement matrix is defined, and by explicating the set of linear displacements on the association matrix, a structural vector is described describing quantitative changes, taking into account the relations of initial variables.The results of the SSDIF analysis indicate that a one-year curriculum of physical education has caused statistically significant changes in motor skills at the global level (p = 0.000). According to the results of the quantitative global changes, they are not particularly significant and extend across a whole set of analyzed variables. The greater the number of variables that contribute to these quantitative changes, but the contributions of some variables to the discriminating function are relatively small, which means that the effects produced are mild, without dramatic changes, and virtually all variables contribute positively.
The aim of this research is to determine the possession of predisposition for the success of doing business management in the sport. The study was conducted on a sample of 120 managers of sports clubs in Tuzla Canton and Brcko District. A sample of 20 variables is drawn from the survey “Do you have the potential to be a manager?”. Survey results showed that 31 respondents possess many skills and abilities that are required for a successful manager, 63 respondents have some of the skills and abilities to successfully manage, and 26 respondents do not possess adequate skills and the ability to successfully manage others.It is obvious that respondents who want to be successful managers need to pay attention to the managerial skills and techniques in which they feel the weakest.It is logical that different levels of management require different levels of given skills and knowledge. At lower levels of management the need for a higher level of technical knowledge is pronounced. The fact is that –top managers, in contrast to managers at lower levels of the organization, must have a high ability of conceptual thinking based on a high degree of creation and imagination. These are the qualities and skills that cannot be acquired through the educational process.
This study was conducted on a sample of 40 senior and junior male and female karate fighters, chronological ages 18 to 27 from the Tuzla Canton, who are part of the regular training and competition process. The aim of this paper is to determine the differences in the motor reaction speed among the karate players with the same specializations but at different levels of competition, in conditions of fatigue induced by intense physical work in combination with complex visual signalization, which determines certain karate techniques. The study was conducted with the application of sophisticated technologies used in sport that enable the collection of data. The light stimuli was generated by the usage of the RIR 102 reaction meter and the quantitative valorization of the investigated parameters was carried out by a sophisticated kinematic analysis of the videos collected using two high-speed Casio Exilim EX-F1 digital cameras synchronized with the data from the Polar Team heart monitoring system. By processing and analyzing data, it was concluded that fatigue induced by situational conditions such as performing a series of strikes that simultaneously generate muscular, cognitive and sensory strain, produces negative effects on reaction time of the karate players. The intensity of limiting factors grows gradually in function of time, but is manifested differently in relation to the international and state level of competition.
ABSTRACT Introduction: Evolocumab is fully human monoclonal antibody which binds to proprotein convertase subtilisin/kexin type 9 (PCSK9), and prevents its blocking effect on recycling of liver low-density lipoprotein (LDL) receptors. Areas covered: The aim of this review is to assess efficacy, safety, and cost-effectiveness of evolocumab in adult patients with high cardiovascular risk. Major research databases MEDLINE, EBSCO, and CENTRAL were systematically searched for relevant study reports. Expert commentary: Even when given in full doses, statins augmented with ezetimibe and cholesterol-binding resins could not reduce cholesterol baseline level for more than 66%, while evolocumab reduces cholesterol level for 75% or even more. Up to now, evolocumab showed good safety profile, and patents tolerate it very well. The abovementioned advantages of evolocumab made it almost ideal drug for hypercholesterolemia, and probably in the future the best drug for secondary prevention of major cardiovascular events. Evolocumab is borderline cost-effective for the treatment of patients with high cardiovascular risk in European countries, while in the U.S.A. it is under debate where the underlying assumption (risk of cardiovascular disease events) determine the true value.
Nema pronađenih rezultata, molimo da izmjenite uslove pretrage i pokušate ponovo!
Ova stranica koristi kolačiće da bi vam pružila najbolje iskustvo
Saznaj više