Autonomous robots path planning: An adaptive roadmap approach

Developing algorithms that allow robots to independently navigate unknown environments is a widely researched area of robotics. The potential for autonomous mobile robots use, in industrial and military applications, is boundless. Path planning entails computing a collision free path from a robots current position to a desired target. The problem of path planning for these robots remains underdeveloped. Computational complexity, path optimization and robustness are some of the issues that arise. Current algorithms do not generate general solutions for different situations and require user experience and optimization. Classical algorithms are computationally extensive. This reduces the possibility of their use in real time applications. Additionally, classical algorithms do not allow for any control over attributes of the generated path. A new roadmap path planning algorithm is proposed in this paper. This method generates waypoints, through which the robot can avoid obstacles and reach its goal. At the heart of this algorithm is a method to control the distance of the waypoints from obstacles, without increasing its computational complexity. Several simulations were run to illustrate the robustness and adaptability of this approach, compared to the most commonly used path planning methods

Sezonska dinamika primarne i sekundarne produkcije u šaranskim ribnjacima

Sezonska dinamika biomase i kvalitativnog sastava fitoplanktona, zooplanktona i makrozoobentosa je istraživana u odnosu na fizičke i hemijske faktore vodene sredine, međusobno kao i u odnosu na gajene ribe u tri zemljana bazena. Fitoplankton je imao veliki diverzitet vrsta, naročito jestivih, tokom prvog dela sezone. Kasnije, sa porastom temperature, ihtiomase, količine ekskreta riba, degradacijom nepojedene hrane kao i povremenim smanjenjem količine vode u jezerima, došlo je do promene u pravcu dominacije filamentoznih Cyanophyta. Zooplankton i makrozoobentos su tokom celog perioda istraživanja imali mali diverzitet vrsta. Sezonalna dinamika zooplanktona se karakterisala dominacijom dve Rotatoria, Brachionus angularis i Keratella tropica i malom Cladocera Bosmina longirostris u sva tri bazena. Makrozoobentos je imao malu gustinu i biomasu, a larvame Chironomidae su dominirale tokom cele sezone

Agricultural Academy

Diversity of the fi sh species important for fi shery on the territory of Serbia has changed both spatially and temporally. Temporal changes are connected with historical and anthropogenic factors, while spatial changes are mostly the results of anthropogenic activity. Based on the analysis of the "BAES-ex situ" national database, there are two temporal and spatial periods. The fi rst period (from 1860 to 1950) is characterised by great diversity of the fi sh species important for fi shery in natural ecosystems, above all in rivers. The second period (from 1950 until today) is characterised by reduction in the diversity of the fi sh species important for fi shery, especially sturgeon species, in natural ecosystems, predominantly rivers, and the increasing diversity in anthropogenic water ecosystems. The increasing diversity in accumulations is predominantly related to Cyprinidae and Percidae species. The reduction in diversity in natural ecosystems is most often the result of irrational fi shery, habitat degradation, prominent anthropogenic infl uence and presence of introduced species. Many species important for fi shery are, according to the newest legal regulations of the Republic of Serbia, classifi ed in the category of strictly protected and protected species, and the permanent close hunting season or close season in certain periods and ban on hunting for individuals below prescribed size was declared for many of them. Taking into consideration prominent reduction in diversity, some of the fi sh species important for fi shery are also in "The preliminary list of species for the Serbian red list of vertebrates" because they are in danger of being extinct

3D-4D Interlinkage Of qqq Wave Functions Under 3D Support For Pairwise Bethe-Salpeter Kernels

Using the method of Green's functions within a Bethe-Salpeter framework characterized by a pairwise qq interaction with a Lorentz-covariant 3D support to its kernel, the 4D BS wave function for a system of 3 identical relativistic spinless quarks is reconstructed from the corresponding 3D form which satisfies a fully connected 3D BSE. This result is a 3-body generalization of a similar 2-body result found earlier under identical conditions of a 3D support to the corresponding qq-bar BS kernel under Covariant Instaneity (CIA for short). (The generalization from spinless to fermion quarks is straightforward). To set the CIA with 3D BS kernel support ansatz in the context of contemporary approaches to the qqq baryon problem, a model scalar 4D qqq BSE with pairwise contact interactions to simulate the NJL-Faddeev equations is worked out fully, and a comparison of both vertex functions shows that the CIA vertex reduces exactly to the NJL form in the limit of zero spatial range. This consistency check on the CIA vertex function is part of a fuller accounting for its mathematical structure whose physical motivation is traceable to the role of `spectroscopy' as an integral part of the dynamics.Comment: 20 pages, Latex, submitted via the account of K.-C. Yan

Monopoles and Knots in Skyrme Theory

We show that the Skyrme theory actually is a theory of monopoles which allows a new type of solitons, the topological knots made of monopole-anti-monopole pair,which is different from the well-known skyrmions. Furthermore, we derive a generalized Skyrme action from the Yang-Mills action of QCD, which we propose to be an effective action of QCD in the infra-red limit. We discuss the physical implications of our results.Comment: 4 pages. Phys. Rev. Lett. in pres

Chiral effective action with heavy quark symmetry

We derive an effective action combining chiral and heavy quark symmetry, using approximate bosonization techniques of QCD. We explicitly show that the heavy-quark limit is compatible with the large $N_c$ (number of color) limit in the meson sector, and derive specific couplings between the light and heavy mesons ($D$, $D^*$, ...) and their chiral partners. The relevance of this effective action to solitons with heavy quarks describing heavy baryons is discussed.Comment: 14 pages, SUNY-NTG-92/2

Search for new phenomena in dijet events using 37 fb−1 of pp collision data collected at √s=13 TeV with the ATLAS detector

Dijet events are studied in the proton-proton collision data set recorded at s=13 TeV with the ATLAS detector at the Large Hadron Collider in 2015 and 2016, corresponding to integrated luminosities of 3.5 fb-1 and 33.5 fb-1 respectively. Invariant mass and angular distributions are compared to background predictions and no significant deviation is observed. For resonance searches, a new method for fitting the background component of the invariant mass distribution is employed. The data set is then used to set upper limits at a 95% confidence level on a range of new physics scenarios. Excited quarks with masses below 6.0 TeV are excluded, and limits are set on quantum black holes, heavy W′ bosons, W∗ bosons, and a range of masses and couplings in a Z′ dark matter mediator model. Model-independent limits on signals with a Gaussian shape are also set, using a new approach allowing factorization of physics and detector effects. From the angular distributions, a scale of new physics in contact interaction models is excluded for scenarios with either constructive or destructive interference. These results represent a substantial improvement over those obtained previously with lower integrated luminosity

Search for supersymmetry in final states with missing transverse momentum and multiple b-jets in proton-proton collisions at √s=13 TeV with the ATLAS detector

A search for supersymmetry involving the pair production of gluinos decaying via third-generation squarks into the lightest neutralino χ˜10 $$\left({\tilde{\chi}}_1^0\right)$$ is reported. It uses LHC proton-proton collision data at a centre-of-mass energy s=13 $$\sqrt{s}=13$$ TeV with an integrated luminosity of 36.1 fb−1 collected with the ATLAS detector in 2015 and 2016. The search is performed in events containing large missing transverse momentum and several energetic jets, at least three of which must be identified as originating from b-quarks. To increase the sensitivity, the sample is divided into subsamples based on the presence or absence of electrons or muons. No excess is found above the predicted background. For χ˜10 $${\tilde{\chi}}_1^0$$ masses below approximately 300 GeV, gluino masses of less than 1.97 (1.92) TeV are excluded at 95% confidence level in simplified models involving the pair production of gluinos that decay via top (bottom) squarks. An interpretation of the limits in terms of the branching ratios of the gluinos into third-generation squarks is also provided. These results improve upon the exclusion limits obtained with the 3.2 fb−1 of data collected in 2015