DETECTION OF TEXTURE-LESS OBJECTS BY LINE-BASED APPROACH

This paper proposes a method for tackling the problem of scalable object instance detection in the presence of clutter and occlusions. It gathers together advantages in respect of the state-of-the-art object detection approaches, being at the same time able to scale favorably with the number of models, computationally efficient and suited to texture-less objects as well. The proposed method has the following advantages: a) generality – it works for both texture-less and textured objects, b) scalability – it scales sub-linearly with the number of objects stored in the object database, and c) computational efficiency – it runs in near real-time. In contrast to the traditional affine-invariant detectors/descriptors which are local and not discriminative for texture-less objects, our method is based on line segments around which it computes semi-global descriptor by encoding gradient information in scale and rotation invariant manner. It relies on both texture and shape information and is, therefore, suited for both textured and texture-less objects. The descriptor is integrated into efficient object detection procedure which exploits the fact that the line segment determines scale, orientation and position of an object, by its two endpoints. This is used to construct several effective techniques for object hypotheses generation, scoring and multiple object reasoning; which are integrated in the proposed object detection procedure. Thanks to its ability to detect objects even if only one correct line match is found, our method allows detection of the objects under heavy clutter and occlusions. Extensive evaluation on several public benchmark datasets for texture-less and textured object detection, demonstrates its scalability and high effectiveness

Additive results for the generalized Drazin inverse in a Banach algebra

AbstractIn this paper we investigate additive properties of the generalized Drazin inverse in a Banach algebra. We find some new conditions under which the generalized Drazin inverse of the sum a+b could be explicitly expressed in terms of a, ad, b, bd. Also, some recent results of Castro and Koliha [New additive results for the g-Drazin inverse, Proc. Roy. Soc. Edinburgh Sect. A 134 (2004) 1085–1097] are extended

Testing the toughness of polypropylene filled with glass powder

Svrha rada je da se polimerni otpad prikaže kao sirovina ili na drugi način iskoristljiv materijal dobijen djelimičnim razdvajanjem komunalnog otpada. U radu je obrađena mogućnost ponovne upotrebe polipropilena recikliranjem uz dodatak staklenog praha, sa stanovišta žilavosti usljed udarnog opterećenja. Ispitivane su standardne epruvete, napravljene od osnovnog materijala - polipropilena i uz dodatak 0%, 5%, 10%, 15%, 20%, 25% i 30% staklenog praha granulacije manje od 0,5 mm, kroz šest ciklusa prerade. Izmjerene vrijednosti dale su mogućnost formiranja obrazaca promjene žilavosti posmatranog materijala sa različitim sadržajem stranog tijela, kroz cikluse prerade, što može pomoći u daljim istraživanjima i analizama.The purpose of this paper is to show polymer waste as a raw material or otherwise usable material derived from a partial separation of communal waste. This paper describes the possibilities of polypropylene re-use through recycling with addition of glass powder, from the point of view of toughness caused by impact load. Standard test specimens, made of basic material - polypropylene, with addition of 0%, 5%, 10%, 15%, 20%, 25% and 30% of glass powder with granulation less than 0,5 mm, have been tested through six processing cycles. The measured values gave a possibility of forming patterns for changes of the observed material with different content of additives, through processing cycles, which can be helpful in further research and analysis

Endovascular aortic repair: First twenty years

Endovascular aortic/aneurysm repair (EVAR) was introduced into clinical practice at the beginning of the nineties. Its fast development had a great influence on clinicians, vascular surgeons and interventional radiologists, educational curriculums, patients, industry and medical insurance. The aim of this paper is to present the contribution of clinicians and industry to the development and advancement of endovascular aortic repair over the last 20 years. This review article presents the development of EVAR by focusing on the contribution of physicians, surgeons and interventional radiologists in the creation of the new field of vascular surgery termed hybrid vascular surgery, and also the contribution of technological advancement by a significant help of industrial representatives – engineers and their counselors. This article also analyzes studies conducted in order to compare the successfulness of EVAR with up-to-now applied open surgical repair of aortic aneurysms, and some treatment techniques of other aortic diseases. During the first two decades of its development the EVAR method was rapidly progressing and was adopted concurrently with the expansion of technology. Owing to large randomized studies, early and long-term results indicate specific complications of this method, thus influencing further technological improvement and defining risk patients groups in whom the use of the technique should be avoided. Good results are insured only in centers, specialized in vascular surgery, which have on their disposal adequate conditions for solving all complications associated with this method

Algebraic proof methods for identities of matrices and operators: improvements of Hartwig's triple reverse order law

When improving results about generalized inverses, the aim often is to do this in the most general setting possible by eliminating superfluous assumptions and by simplifying some of the conditions in statements. In this paper, we use Hartwig's well-known triple reverse order law as an example for showing how this can be done using a recent framework for algebraic proofs and the software package OperatorGB. Our improvements of Hartwig's result are proven in rings with involution and we discuss computer-assisted proofs that show these results in other settings based on the framework and a single computation with noncommutative polynomials

Equalities of ideals associated with two projections in rings with involution

In this article we study various right ideals associated with two projections (self-adjoint idempotents) in a ring with involution. Results of O.M. Baksalary, G. Trenkler, R. Piziak, P.L. Odell and R. Hahn about orthogonal projectors (complex matrices which are Hermitian and idempotent) are considered in the setting of rings with involution. New proofs based on algebraic arguments, rather than finite-dimensional and rank theory, are given.The authors thank the anonymous reviewer for his\her useful suggestions, which helped to improve the original version of this article. The second author is supported by Grant No. 174007 of the Ministry of Science, Technology and Development, Republic of Serbia.Benítez López, J.; Cvetkovic-Ilic, D. (2013). Equalities of ideals associated with two projections in rings with involution. Linear and Multilinear Algebra. 61(10):1419-1435. doi:10.1080/03081087.2012.743026S141914356110Baksalary, O. M., & Trenkler, G. (2009). Column space equalities for orthogonal projectors. Applied Mathematics and Computation, 212(2), 519-529. doi:10.1016/j.amc.2009.02.042Benítez, J. (2008). Moore–Penrose inverses and commuting elements of C∗-algebras. Journal of Mathematical Analysis and Applications, 345(2), 766-770. doi:10.1016/j.jmaa.2008.04.062Green, J. A. (1951). On the Structure of Semigroups. The Annals of Mathematics, 54(1), 163. doi:10.2307/1969317Harte, R. (1992). On generalized inverses in C*-algebras. Studia Mathematica, 103(1), 71-77. doi:10.4064/sm-103-1-71-77Harte, R. (1993). Generalized inverses in C*-algebras II. Studia Mathematica, 106(2), 129-138. doi:10.4064/sm-106-2-129-138Koliha, J. J. (2000). Elements of C*-algebras commuting with their Moore-Penrose inverse. Studia Mathematica, 139(1), 81-90. doi:10.4064/sm-139-1-81-90Koliha, J. J., Cvetković-Ilić, D., & Deng, C. (2012). Generalized Drazin invertibility of combinations of idempotents. Linear Algebra and its Applications, 437(9), 2317-2324. doi:10.1016/j.laa.2012.06.005Koliha, J. J., & Rakočević, V. (2003). Invertibility of the Difference of Idempotents. Linear and Multilinear Algebra, 51(1), 97-110. doi:10.1080/030810802100023499Mary, X. (2011). On generalized inverses and Green’s relations. Linear Algebra and its Applications, 434(8), 1836-1844. doi:10.1016/j.laa.2010.11.045Von Neumann, J. (1936). On Regular Rings. Proceedings of the National Academy of Sciences, 22(12), 707-713. doi:10.1073/pnas.22.12.707Patrı́cio, P., & Puystjens, R. (2004). Drazin–Moore–Penrose invertibility in rings. Linear Algebra and its Applications, 389, 159-173. doi:10.1016/j.laa.2004.04.006Piziak, R., Odell, P. L., & Hahn, R. (1999). Constructing projections on sums and intersections. Computers & Mathematics with Applications, 37(1), 67-74. doi:10.1016/s0898-1221(98)00242-

Phytochemistry, Toxicology and Therapeutic Value of Petasites hybridus Subsp. Ochroleucus (Common Butterbur) from the Balkans

Petasites hybridus (Common butterbur) is extensively used in traditional medicine, and is currently gaining interest and popularity as a food supplement and for its medicinal properties. It contains a large number of active compounds of potential therapeutic activity, but also toxic pyrrolizidine alkaloids. Science-based information is needed to support the developing modern use of this plant, and to direct continued safe practice in traditional medicine. The present study focused on the essential oils from leaves and rhizomes of the understudied P. hybridus ssp. ochroleucus from the Balkans, and evaluated its phytochemistry and potential therapeutic activities (antimicrobial, antioxidant, anti-cholinesterase and anti-inflammatory), as well its toxicology potential (acute toxicity in insects and mice). We studied the essential oils, which are not commonly used in traditional practices, but have a potential for safe use since the toxic pyrrolizidine alkaloids, which are non-volatiles, are usually not present in the distilled essential oils. Pyrrolizidine alkaloids were indeed not detected in the essential oils; ingestion of the essential oils did not induce toxicity signs in mice, and topical application did not elicit skin irritation in humans. The essential oils had no antimicrobial properties against 20 pathogenic bacterial strains, but demonstrated good local anti-inflammatory activity in a Carrageenan-induced paw edema test. An insect toxicity test demonstrated that the leaf essential oil is an efficient insect repellent, and the demonstrated anti-cholinesterase activity suggests a potential for the treatment of neurological conditions. Isopetasin, a sesquiterpene found in plants of the genus Petasites, known to have anti-inflammatory effects, was present only in the rhizomes essential oil (3.9%), and sesquiterpene lactones concentrations were high, likely contributing to the antioxidant activity

Some additive results on Drazin inverse

In this paper, we investigate additive results of the Drazin inverse of elements in a ring R. Under the condition ab = ba, we show that a + b is Drazin invertible if and only if aa^D(a+b) is Drazin invertible, where the superscript D means the Drazin inverse. Furthermore we find an expression of (a + b)^D. As an application we give some new representations for the Drazin inverse of a 2 × 2 block matrix.Supported by the National Natural Science Foundation of China (11361009), the Guangxi Provincial Natural Science Foundation of China (2013GXNSFAA019008), and Science Research Project 2013 of the China-ASEAN Study Center (Guangxi Science Experiment Center) of Guangxi University for Nationalities.Liu, X.; Qin, X.; Benítez López, J. (2015). Some additive results on Drazin inverse. Applied Mathematics - A Journal of Chinese Universities. 30(4):479-490. https://doi.org/10.1007/s11766-015-3333-4S479490304A Ben-Israel, T N E Greville. Generalized Inverses, Theory and Applications, 2nd edition, Springer-Verlag, 2003.S L Campbell, C D Meyer. Generalized Inverses of Linear Transformations, Pitman (Advanced Publishing Program), Boston, MA, 1979.N Castro-González, J J Koliha. Additive perturbation results for the Drazin inverse, Linear Algebra Appl, 2005, 397: 279–297.N Castro-González, E Dopazo, M F Martínez-Serrano. On the Drazin inverse of the sum of two operators and its application to operator matrices, J Math Anal Appl, 2008, 350: 207–215.N Castro-González, M F Martínez-Serrano. Expressions for the g-Drazin inverse of additive perturbed elements in a Banach algebra, Linear Algebra Appl, 2010, 432: 1885–1895.N Castro-González, J J Koliha. New additive results for the Drazin inverse, Proc Roy Soc Edinburgh Sect A, 2004, 134: 1085–1097.M Catral, D D Olesky, P van den Driessche. Block representations of the Drazin inverse of a bipartite matrix, Electron J Linear Algebra, 2009, 18: 98–107.J L Chen, G F Zhuang, Y Wei. The Drazin inverse of a sum of morphisms, Acta Math Sci Ser A Chin Ed, 2009, 29(3): 538–552.D S Cvetković-Ilić, D S Djordjević, Y Wei. Additive results for the generalized Drazin inverse in a Banach algebra, Linear Algebra Appl, 2006, 418, 53–61.D S Cvetković-Ilić. A note on the representation for the Drazin inverse of 2 × 2 block matrices, Linear Algebra Appl, 2008, 429: 242–248.C Deng. The Drazin inverses of sum and difference of idempotents, Linear Algebra Appl, 2009, 430: 1282–1291.C Deng, Y Wei. Characterizations and representations of the Drazin inverse of idempotents, Linear Algebra Appl, 2009, 431: 1526–1538.C Deng, Y Wei. New additive results for the generalized Drazin inverse, J Math Anal Appl, 2010, 370: 313–321.D S Djordjević, P S Stanimirović. On the generalized Drazin inverse and generalized resolvent, Czechoslovak Math J, 2001, 51(126): 617–634.D S Djordjević, Y Wei. Additive results for the generalized Drazin inverse, J Aust Math Soc, 2002, 73: 115–125.D S Djordjević, V Rakočević. Lectures on Generalized inverses, University of Niš, 2008.E Dopazo, M F Martínez-Serrano. Further results on the representation of the Drazin inverse of a 2 × 2 block matrices, Linear Algebra Appl, 2010, 432: 1896–1904.M P Drazin. Pseudo-inverses in associative rings and semiproup, Amer Math Monthly, 1958, 65: 506–514.R E Hartwig, G R Wang, Y Wei. Some additive results on Drazin inverse, Linear Algebra Appl, 2001, 322: 207–217.R E Hartwig, X Li, Y Wei. Representations for the Drazin inverse of a 2×2 block matrix, SIAM J Matrix Anal Appl, 2006, 27: 757–771.Y Liu, C G Cao. Drazin inverse for some partitioned matrices over skew fields, J Nat Sci Heilongjiang Univ, 2004, 24: 112–114.J Ljubisavljević, D S Cvetković-Ilić. Additive results for the Drazin inverse of block matrices and applications, J Comput Appl Math, 2011, 235: 3683–3690.C D Meyer ffixJr, N J Rose. The index and the Drazin inverse of block triangular matrices, SIAM J Appl Math, 1977, 33(1): 1–7.L Wang, H H Zhu, X Zhu, J L Chen. Additive property of Drazin invertibility of elements, arXiv: 1307.1816v1 [math.RA], 2013.H Yang, X Liu. The Drazin inverse of the sum of two matrices and its applications, J Comput Appl Math, 2011, 235: 1412–1417

Actual contamination of the Danube and Sava Rivers at Belgrade (2013)

This study was focussed on a comprehensive investigation on the state of pollution of the Danube and Sava Rivers in the region of Belgrade. Different complementary analytical approaches were employed covering both i) organic contaminants in the river water by target analyses of hormones and neonicotinoids as well as non-target screening analyses and ii) heavy metals in the sediments. Finally, some common water quality parameters were analysed. The overall state of pollution is on a moderate level. Bulk parameters did not reveal any unusual observations. Moreover, quantification of preselected organic contaminants did not indicate to elevated pollution. More significant contaminations were registered for chromium, nickel, zinc and partially copper in sediments with values above the target values according to Serbian regulations. Lastly, non-target screening analysis revealed a wider spectrum of organic contaminants comprising pharmaceuticals, technical additives, personal care products and pesticides. The study presented a comprehensive view on the state of pollution of the Sava and Danube Rivers and is the base for setting up further monitoring programs. As a superior outcome, it was illustrated how different chemical analyses can result in different assessments of the river quality. A comparison of target and non-target analyses pointed to potential misinterpretation of the real state of pollution