Asymptotically false-positive-maximizing attack on non-binary Tardos codes

We use a method recently introduced by Simone and Skoric to study accusation probabilities for non-binary Tardos fingerprinting codes. We generalize the pre-computation steps in this approach to include a broad class of collusion attack strategies. We analytically derive properties of a special attack that asymptotically maximizes false accusation probabilities. We present numerical results on sufficient code lengths for this attack, and explain the abrupt transitions that occur in these results

Stanje površinskog sloja materijala obratka kod visokoučinskog brušenja

This paper focuses on the development of high temperatures in the cutting zone during high performance grinding. In order to identify the influence of grinding temperature on surface integrity, temperatures were measured in the workpiece surface layer under different machining conditions. Beside this, under the same conditions, the surface layer properties of the workpiece material were determined through metallographic examination. Microstructureand microhardness of the workpiece surface layer, as well as the burned surfaces and microcracks phenomena were investigated. The conducted experimental investigations allow the surface layer properties of the workpiece material in high performance grinding to be defined.U članku se ukazuje na pojavu visokih temperatura u zoni rezanja pri visokoučinskom brušenju. Da bi se ustanovio utjecaj temperature brušenja na kvalitet obrađene površine, izmjerene su temperature u površinskom sloju materijala obratka pri različitim uvjetima obrade. Ujedno je pri istim uvjetima obrade određeno stanje površinskog sloja materijala obratka metalografskim ispitivanjima. Ispitane su mikrostruktura i mikrotvrdoća površinskog sloja obratka i pojava nagorjelih površina i mikropukotina. Izvedena eksperimentalna istraživanja defi niraju stanje površinskog sloja materijala obratka kod visokoučinskog brušenja

Karakterizacija dupleks tvrdih prevlaka sa dodatnom ionskom primjenom

In this paper, we present the results of a study of TiN thin films which are deposited by a Physical Vapour Deposition (PVD) and Ion Beam Assisted Deposition (IBAD). In the present investigation the subsequent ion implantation was provided with N+2 ions. The ion implantation was applied to enhance the mechanical properties of surface. The thin film deposition process exerts a number of effects such as crystallographic orientation, morphology, topography, densification of the films. The evolution of the microstructure from porous and columnar grains to densel packed grains is accompanied by changes in mechanical and physical properties. A variety of analytic techniques were used for characterization, such as scratch test, calo test, Scanning electron microscopy (SEM), Atomic Force Microscope (AFM), X-ray diffraction (XRD) and Energy Dispersive X-ray analysis (EDAX).U ovom radu pretstavljaju se rezultati istraživanja TiN tankih fi lmova, nanešenih fi zičkim odlaganjem iz parne faze i te podržani ionskim snopom. U ovom istraživanju je izvršena i naknadna ionska primjena sa N+2 ionima. Ionska primjena je sprovedena radi poboljšanja mehaničkih svojstava površina. Proces nanošenja tankih fi lmova karakterizira veliki broj učinaka, kao što su: kristalografska orijentacija, morfologija, topografi ja, gustoća fi lma. Razvoj mikrostrukture od porozne i stubaste u zrnastu gusto pakovanu, se dešava uz istovremenu promjenu mehaničkih i fi zičkih svojstava. Za karakterizaciju su rabljene različite analitičke tehnike, kao što su test zaparavanja, kalo test, skenirajući elektronski mikroskop (SEM), mikroskop atomskih sila (AFM), rentgenska difrakcija X zraka (XRD) i energijska disperzivna analiza X zraka (EDAX)

Characterization of duplex hard coatings with additional ion implantation

In this paper, we present the results of a study of TiN thin fi lms which are deposited by a Physical Vapour Deposition (PVD) and Ion Beam Assisted Deposition (IBAD). In the present investigation the subsequent ion implantation was provided with N⁺² ions. The ion implantation was applied to enhance the mechanical properties of surface. The thin film deposition process exerts a number of eff ects such as crystallographic orientation, morphology, topography, densifi cation of the fi lms. The evolution of the microstructure from porous and columnar grains to densel packed grains is accompanied by changes in mechanical and physical properties. A variety of analytic techniques were used for characterization, such as scratch test, calo test, Scanning electron microscopy (SEM), Atomic Force Microscope (AFM), X-ray diff raction (XRD) and Energy Dispersive X-ray analysis (EDAX)

Molecular identification of a phytoplasma infecting grapevine in the Republic of Macedonia

Phytoplasmas from the ribosomal subgroup 16SrXII-A (stolbur) were identified by PCR and RFLP analyses of 16S rRNA gene and elongation factor-Tu phytoplasma gene (tuf) in symptomatic grapevines from the Veles and Skopje areas in Macedonia. Two methods were used for nucleic acid extraction. Amplification and RFLP results of 16S rDNA were not influenced by the method used, but RFLP patterns of tuf gene revealed additional bands if a less time consuming method was applied. The possible origin of these bands is discussed. This is the first report of the presence of the stolbur phytoplasma in cvs Chardonnay and Vranac in Macedonia.

Greater Expectations?

Physically Unclonable Functions (PUFs) are key tools in the construction of lightweight authentication and key exchange protocols. So far, all existing PUF-based authentication protocols follow the same paradigm: A resource-constrained prover, holding a PUF, wants to authenticate to a resource-rich verifier, who has access to a database of pre-measured PUF challenge-response pairs (CRPs). In this paper we consider application scenarios where all previous PUF-based authentication schemes fail to work: The verifier is resource-constrained (and holds a PUF), while the prover is resource-rich (and holds a CRP-database). We construct the first and efficient PUF-based authentication protocol for this setting, which we call converse PUF-based authentication. We provide an extensive security analysis against passive adversaries, show that a minor modification also allows for authenticated key exchange and propose a concrete instantiation using controlled Arbiter PUFs

(Mis-)handling gauge invariance in the theory of the quantum Hall effect III: The instanton vacuum and chiral edge physics

The concepts of an instanton vacuum and F-invariance are used to derive a complete effective theory of massless edge excitations in the quantum Hall effect. We establish, for the first time, the fundamental relation between the instanton vacuum approach and the theory of chiral edge bosons. Two longstanding problems of smooth disorder and Coulomb interactions are addressed. We introduce a two dimensional network of chiral edge states and tunneling centers (saddlepoints) as a model for the plateau transitions. We derive a mean field theory including the Coulomb interactions and explain the recent empirical fits to transport at low temperatures. Secondly, we address the problem of electron tunneling into the quantum Hall edge. We express the problem in terms of an effective Luttinger liquid with conductance parameter (g) equal to the filling fraction (\nu) of the Landau band. Hence, even in the integral regime our results for tunneling are completely non-Fermi liquid like, in sharp contrast to the predictions of single edge theories.Comment: 51 pages, 8 figures; section IIA3 completely revised, section IIB and appendix C corrected; submitted to Phys.Rev.

Kvalitet i tehničko-tehnološke karakteristike semena oleinskog suncokreta

The quality and technical-technological characteristics of oleic type sunflower seed grown at four localities were analyzed and compared with seed of domestic hybrids of linoleic type, from mss production. The basic quality parameters were determined: oil and protein content, fatty acid composition and total tocopherols content, as well as the most important characteristics which affect the quality of separated crude oil: free fatty acids and peroxide value. Besides standard (usual) technical-technological characteristics of seed, like liter and specific mass, mass of 100 grains portion of hull and kernel etc, the hull hygroscopicity was investigated and seed dimensions were determined. The obtained results have shown that the oleic sunflowerseed hybrid - Olivko - has a high content of oleic acid, about 80%, oil content (on dry matter) is over 50%, and the protein content of the seed is about 22%. According to acidity and oxidative state, the seed is of very good quality and can be used for the obtaining of cold pressed oil. However, the seed is quite small, the hull is rather thin and there are certain differences in hull hygroscopicity. The different localities had no significant influence on the mentioned quality characteristics.U radu je analiziran kvalitet i tehničko-tehnološke karakteristike semena oleinskog suncokreta gajenog na četiri lokaliteta u odnosu na seme linolnog tipa domaćih hibrida iz masovne proizvodnje. U uzorcima su određeni osnovni pokazatelji kvaliteta: sadržaj ulja i proteina, zatim sastav masnih kiselina i sadržaj ukupnih tokoferola, kao i najbitniji pokazatelji koji neposredno uslovljavaju kvalitet izdvojenog sirovog ulja: slobodne masne kiseline i peroksidni broj. Osim standardnih tehničko-tehnoloških karakteristika semena kao što su: litarska i specifična masa, masa 1000 zrna, udeo ljuske i jezgra itd. ispitana je higroskopnost ljuske i određene su dimenzije semena. Dobijeni rezultati su pokazali da oleinski hibrid suncokreta – Olivko – ima visok sadržaj oleinske kiseline, oko 80%, sadržaj ulja na suvu materiju je preko 50%, a sadržaj proteina u semenu je oko 22%. Prema kiselosti i oksidativnom stanju seme je veoma dobrog kvaliteta za dobijanje hladno ceđenog ulja. Međutim, seme je dosta sitno, ljuska je prilično tanka i postoje određene razlike u higroskopnosti ljuske. Različiti lokaliteti uzgoja nisu značajno uticali na navedene pokazatelje kvaliteta semena

Sorption of textile dyes from textile wastewater by chitosan-based hydrogel

With the excessive risks that are present in today's environment, it is of great importance to treat wastewaters before their discharge in water streams. One of the everyday challenges is design of a low-cost and environmentally friendly sorbent such as hydrogel based on chitosan, itaconic and methacrylic acid that can remove wide range of textile dyes. In the present study, this hydrogel has been utilized for investigation of removal of three different azo dyes from simulated textile wastewater: C.I. Basic Blue 9, C.I. Basic Red 1 and C.I. Acid Orange 7. It was found that pH value of the solution had significant effect on dye sorption. Removal of basic dyes was successful at higher pH values, while sorption of acid dye was possible only at low pH value of solution. Simulated textile wastewater is a complex system with various salts, acids and polymers present beside dyes. Regardless of these components, excellent sorption capacity was achieved (more than 80% of dyes were removed), which makes this hydrogel attractive for use under real conditions