401 research outputs found
DISTRIBUTED CONSENSUS-BASED CALIBRATION OF NETWORKED CONTROL SYSTEMS
In this paper a new algorithm for distributed blind macro-calibration of Networked Control Systems is presented. It is assumed that the measured signal is stochastic and unknown. The algorithm is in the form of recursions of gradient type for estimation of the correction parameters for sensor gains and offsets. The recursion for gain correction is autonomous, derived from the measurement increments. The recursion for offset correction is based on differences between local measurements and utilizes the results of gain correction. It is proved that the algorithm provides asymptotic convergence to consensus in the sense that the corrected gains and offsets are equal for all sensors. It is demonstrated that the adopted structure of the algorithm enables obtaining high convergence rate, superior to the algorithms existing in the literature. Simulation results are provided illustrating the proposed algorithm properties
Antimicrobial treatment of cattle hides to improve microbial safety of beef meat
U radu je ispitan i razvijen novi pristup tretmanu kože goveda prirodnom smolom šelak, koja je dozvoljena za korišćenje u hrani, u cilju redukcije unakrsne mikrobiološke kontaminacije sa kože na goveđe meso. Mehanizam ovog tretmana je baziran na imobilizaciji mikroorganizama na dlaci tretirane kože i prevenciji njihovog fizičkog prenosa sa dlake na meso trupova tokom procesa obrade zaklanih goveda. U in vitro uslovima, tretman uzoraka vizuelno čiste i suve kože 23% rastvorom šelaka u etanolu je redukovao prenos sa kože na sunđere kojima je koža uzorkovana brisevima: ukupne mikroflore (TVC) za 6,6 log (>1000 puta više u odnosu na 2,9 log redukcije kod tretmana samo etanolom), generičke Escherichia coli za najmanje 2,9 i Enterobacteriaceae za najmanje 4,8 log. Ove redukcije sve tri grupe mikroorganizama su bile značajno više u odnosu na redukcije postignute tretmanom kože kombinacijom ispiranja sanitajzerom i vakumiranja. Značajno više redukcije prenosa TVC sa kože na sunđerske briseve su postignute korišćenjem viših koncentracija šelaka (23% i 30%) u odnosu na niže (4,8-16,7%) i u slučajevima kada je temperatura rastvora šelaka bila 20, 30 ili 40oC u odnosu na 50oC i 60oC. Takođe, tretman kože šelakom je značajno (3,7 puta) redukovao prevalencu E. coli O157 na prirodno kontaminiranoj, neinokulisanoj koži, kao i broj E. coli O157 na veštački inokulisanim kožama (redukcija od 2,1 log), u odnosu na odgovarajuće netretirane kontrole. U uslovima laboratorijskog modela direktnog kontakta kože i mesa, tretman kože (različitih kategorija čistoće) 23% rastvorom šelaka je značajno smanjio prenos mikroorganizama sa tretirane kože na sterilno goveđe meso: do 3,6 log cfu/cm2 redukcije ukupnog broja bakterija (TVC), do 2,5 log cfu/cm2 Enterobacteriaceae (EC) i do 1,7 log cfu/cm2 generičke E. coli (GEC). Redukcija prenosa TVC je bila značajno viša, a redukcije EC i GEC slične, u odnosu na redukcije nakon tretiranja kože kombinacijom ispiranja-vakumiranja sanitajzerom. U uslovima male komercijalne klanice sa nezadovoljavajućom procesnom praksom (klanje prljavih goveda i neadekvatna higijena procesa klanja i obrade), tretman koža zaklanih goveda 23% rastvorom šelaka je rezultirao značajnom mikrobnom redukcijom na mesu trupova goveda nakon skidanja kože: 1,7 log cfu/cm2 TVC, 1,4 log cfu/cm2 EC i 1,3 log cfu/cm2 GEC. Redukcija TVC na mesu trupova je bila značajno viša, a redukcije EC i GEC slične, u odnosu na redukcije nakon tretiranja kože ispiranjem-vakumiranjem sanitajzerom. Ova istraživanja su po prvi put pružila naučne dokaze da se tretman kože goveda u cilju imobilizacije mikroflore na dlaci može uspešno koristiti u cilju smanjenja kontaminacije mesa trupova tokom procesa skidanja kože, unapređenja finalnog mikrobiološkog statusa mesa i bezbednosti goveđeg mesa uopšte. Da bi se ostvario puni potencijal ovog novog tretmana u praksi, neophodna su dalja istraživanja u cilju njegove tehničke optimizacije u uslovima industrije mesa.In this research, a new approach to cattle hide treatments, based on using a natural, food-grade resin, Shellac, to reduce microbial cross-contamination from the hides onto carcass meat, was developed and evaluated. The basis of this treatment is immobilisation of microorganisms on cattle hide’s hair and subsequent reduction of their transmissibility from the hair onto carcass meat during dressing of slaughtered cattle. Under in vitro conditions, treatment of samples of visually clean and dry hides with 23% Shellac-in-ethanol solution reduced sponge-swabbing recoveries of general microflora (TVC) by a factor of 6.6 logs (>1000-fold greater than the 2.9 log reduction observed by ethanol alone), and of generic E. coli (GEC) and Enterobacteriaceae (EC) by factors of at least 2.9 and 4.8 logs, respectively. The reductions of these three groups of microorganisms were superior to those achieved by a sanitizer rinse-vacuum hide treatment. Significantly greater reductions of TVC recoveries from hides were achieved when using higher Shellac concentrations (23.0% and 30.0% rather than 4.8-16.7%) and when Shellac solution temperatures were 20-40°C rather than 50-60°C. Furthermore, the Shellac-based treatment also markedly reduced the E. coli O157 prevalence (3.7-fold reduction) on natural, uninoculated hides, as well as the counts of E. coli O157 on artificially inoculated hides (2.1 log reduction) when compared to corresponding untreated controls. Under the conditions of a hide-to-meat direct contact laboratory-based model, treatment of hides (of varying visual cleanliness) with the 23% Shellac solution produced significant reductions of microbial transfer from treated hide onto sterile beef: up to 3.6 log10 CFU/cm2 of TVC, up to 2.5 log10 CFU/cm2 of EC and up to 1.7 log10 CFU/cm2 of GEC. TVC reductions of microbial transfer from treated hide onto beef achieved by the Shellac hide treatment were superior to those achieved by the comparative sanitizer rinse-vacuum hide treatment, but reductions of EC and GEC did not differ between the two hide treatments. In a small commercial abattoir with unsatisfactory process practices (slaughtering dirty cattle, inadequate process hygiene), treatment of hides with Shellac produced significant microbial reductions on skinned beef carcasses: 1.7 log10 CFU/cm2, 1.4 log10 CFU/cm2 and 1.3 log10 CFU/cm2 of TVC, EC and GEC, respectively. TVC reductions on skinned beef carcasses achieved by the Shellac hide treatment were superior to those achieved by the comparative sanitizer rinse-vacuum hide treatment, but reductions of EC and GEC did not differ significantly between the two hide treatments. These investigations produced the first scientific evidence that treatment of cattle hides with aim of immobilising microflora on the hair can be very successfully used to reduce carcass meat contamination during the skinning operation, thus improving the microbiological status of the final beef carcasses as well as the beef safety in general. To achieve the full potential of this new treatment in practice, further research aimed at its further technical optimization under real-life meat industry conditions is necessary
ESTIMATION POSITION AND DIAMETER OF REBAR BY MODERN NON-DESTRUCTIVE TECHNIQUES
Ultrasonic testing of concrete by modern equipment has grown in importance in recent years in non-destructive testing. Measuring concrete cover thickness and estimating steel rebar position and diameter is main focus for assessment of existing reinforcement concrete facilities. Voids, entrained air and potential delamination are important to detect in order to evaluate the quality of the executed concrete members. This paper presents the latest two modern non-destructive techniques – ultrasonic tomography and electromagnetic pulse induction – suitable for testing reinforcement concrete members. The capabilities of these techniques for locating defects, reinforcement bars and determining their size in unilaterally accessible concrete members are described
Phylogeny, biogeography and post-embryonic development of representatives of the Holartic family Anthroleucosomatidae Verhoeff, 1899 (Myriapoda, Diplopoda, Chordeumatida).
Holarktička porodica Anthroleucosomatidae jedna je od najheterogenijih i
najproblematičnih porodica u okviru klase Diplopoda. U mnogim radovima je označavana kao
„noćna mora“ i u mnogim slučajevima je služila kao „korpa za otpatke“ za taksone hordeumatida
koji nisu mogli biti uvršteni u neke bolje definisane porodice. Stoga je ova disertacija fokusirana
na rešavanju kompleksnih sistematskih, filogenetskih, biogeografskih i razvojnih odnosa među
predstavnicima porodice Anthroleucosomatidae.
Kako se radi o porodici sa mnogobrojnim premeštanjima taksona unutar i izvan nje, u
uvodnom delu teze dat je kompletan, hronološki i taksativan istorijat proučavanja taksonomije i
sistematike porodice Anthroleucosomatidae. Navedeni su svi taksoni koji su počev od 1876. pa
zaključno sa 2016. godinom svrstavani u navedenu porodicu.
U prvom delu ove doktorske disertacije, na osnovu čitavog niza relevantnih uporednomorfoloških
karaktera, kao i biogeografskih osobenosti, izvršen je rearanžman 35 rodova
antroleukozomatida, sa ukupno 84 vrste, u 12 kompleksa rodova — Alloiopus, Anamastigona,
Anthroleucosoma, Bulgarosoma, Caucaseuma, Dentatosoma, Enghoffiella, Flagellophorella,
Herculina, Leschius, Ratcheuma i Vegrandosoma. Polovina ovih kompleksa uključuje samo po
jedan rod, dok su tri monotipska. Za svaki kompleks je dat kratak opis njegovih pripadnika sa
opisima najbitnijih uporedno-morfoloških karaktera, a pre svega strukture anteriornih i
posteriornih gonopoda, kao i pregonopodalnih nogu kod mužjaka. U okviru nekih kompleksa
izvršena je podela na nekoliko grupa vrsta. Ovi kompleksi predstavljaju osnovu za uspostavljanje
suprageneričkih kategorija. Rodovi Bulgardicus, Camptogona i Ghilarovia su isključeni iz
porodice Anthroleucosomatidae. Za određivanje filogenetskih odnosa između kompleksa rodova
i unutar njih uključen je veći broj karaktera mužjaka, pre svega struktura njihovih gonopoda koja
ima najveći informacioni značaj u filogenetskim razmatranjima. Dobro razvijeni telopoditi na
gonopodama mužjaka smatraju se pleziomorfnim stanjem karaktera kod Diplopoda, pa je na
osnovu njihovog prisustva ili odsustva, kao i strukture utvrđeno da postoji više filetičkih linija
antroleukozomatida, čak i u okviru određenih kompleksa rodova..
ON DESIGN OF SELF-TUNING ACTIVE FILTERS
In this paper, we present one approach in design of self-tuning all-pass, band-pass, low-pass and notch filters based on phase control loops with voltage-controlled active components and analyze their stability as well. The main idea is to vary signal delay of the filter and in this way to achieve phase correction. The filter phase characteristics are tuned by varying the transconductance of the operational transconductance amplifier or capacitance of an MOS varicap element, which are the constituents of filters. This approach allows us to implement active filters with capacitance values of order of pF, making the complete filter circuit to be amenable for realization in CMOS technology. The phase control loops are characterized by good controllable delay over the full range of phase and frequency regulation, high stability, and short settling (locking) time. The proposed circuits are suitable for implementation as a basic building RF function block, used in phase and frequency regulation, frequency synthesis, clock generation recovery, filtering, selective amplifying etc
Nove vrste dvojenoga (Myriapoda, Diplopoda) iz podzemnih staništa Hrvatske
U zadnjem desetljeću nekoliki novih i zanimljivih vrsta dvojenoga je opisano iz špilja i jama Hrvatske. U ovom kratkom članku predstavili smo deset novih vrsta iz tri različita reda: Balkanodesmus biokovensis Antić & Reip, 2014, Solentanodesmus insularis Antić & Reip, 2014, Velebitodesmus cavernicolus Antić & Reip, 2014 (svi red Polydesmida), Egonpretneria vudutschajldi Antić & Dražina, 2015, Biokoviella mosorensis Antić & Dražina, 2016, Dalmatosoma agaricum Antić & Makarov, 2018 (svi red Chordeumatida), Typhloiulus clavatus Antić, 2018, T. gracilis Antić, 2018, T. opisthonodus Antić, 2018, & T. parvulus Antić & Dražina, 2018 (svi red Julida). Gotovo sve vrste (osim T. parvulus) su endemične za Hrvatsku i predstavljaju posebne filetičke linije vezane za Dinaridsko područje. Endemizam nije prisutan samo na razini vrste – Balkanodesmus, Solentanodesmus, Velebitodesmus, Egonpretneria, Biokoviella i Dalmatosoma su endemični rodovi za Hrvatsku. Nadalje, zbog jedinstvenih anatomskih detalja kod vrste D. agaricum uspostavljena je nova monotipska porodica – Dalmatosomatidae. Navedeni rezultati potvrđuju Dinaridski krš kao izrazito važno područje za biološku raznolikost podzemne faune
STABILITY, FINITE-TIME STABILITY AND PASSIVITY CRITERIA FOR DISCRETE-TIME DELAYED NEURAL NETWORKS
In this paper, we present the problem of stability, finite-time stability and passivity for discrete-time neural networks (DNNs) with variable delays. For the purposes of stability analysis, an augmented Lyapunov-Krasovskii functional (LKF) with single and double summation terms and several augmented vectors is proposed by decomposing the time-delay interval into two non-equidistant subintervals. Then, by using the Wirtinger-based inequality, reciprocally and extended reciprocally convex combination lemmas, tight estimations for sum terms in the forward difference of LKF are given. In order to relax the existing results, several zero equalities are introduced and stability criteria are proposed in terms of linear matrix inequalities (LMIs). The main objective for the finite-time stability and passivity analysis is how to effectively evaluate the finite-time passivity conditions for DNNs. To achieve this, some weighted summation inequalities are proposed for application to a finite-sum term appearing in the forward difference of LKF, which helps to ensure that the considered delayed DNN is passive. The derived passivity criteria are presented in terms of linear matrix inequalities. Some numerical examples are presented to illustrate the proposed methodology
Nove vrste dvojenoga (Myriapoda, Diplopoda) iz podzemnih staništa Hrvatske
U zadnjem desetljeću nekoliki novih i zanimljivih vrsta dvojenoga je opisano iz špilja i jama Hrvatske. U ovom kratkom članku predstavili smo deset novih vrsta iz tri različita reda: Balkanodesmus biokovensis Antić & Reip, 2014, Solentanodesmus insularis Antić & Reip, 2014, Velebitodesmus cavernicolus Antić & Reip, 2014 (svi red Polydesmida), Egonpretneria vudutschajldi Antić & Dražina, 2015, Biokoviella mosorensis Antić & Dražina, 2016, Dalmatosoma agaricum Antić & Makarov, 2018 (svi red Chordeumatida), Typhloiulus clavatus Antić, 2018, T. gracilis Antić, 2018, T. opisthonodus Antić, 2018, & T. parvulus Antić & Dražina, 2018 (svi red Julida). Gotovo sve vrste (osim T. parvulus) su endemične za Hrvatsku i predstavljaju posebne filetičke linije vezane za Dinaridsko područje. Endemizam nije prisutan samo na razini vrste – Balkanodesmus, Solentanodesmus, Velebitodesmus, Egonpretneria, Biokoviella i Dalmatosoma su endemični rodovi za Hrvatsku. Nadalje, zbog jedinstvenih anatomskih detalja kod vrste D. agaricum uspostavljena je nova monotipska porodica – Dalmatosomatidae. Navedeni rezultati potvrđuju Dinaridski krš kao izrazito važno područje za biološku raznolikost podzemne faune
NEW CLASS OF DIGITAL MALMQUIST-TYPE ORTHOGONAL FILTERS BASED ON THE GENERALIZED INNER PRODUCT; APPLICATION TO THE MODELING DPCM SYSTEM
A new class of cascade digital orthogonal filters of the Malmquist type based on bilinear transformation for mapping poles to zeroes and vice versa is presented in this paper. In a way, it is a generalization of the majority of the classical orthogonal filters and some newly designed filters as well. These filters are orthogonal with respect to the generalized inner product which is actually a generalization of the classical inner product. Outputs of these filters are obtained by using polynomials orthogonal with respect to the new inner product. The main quality of these filters is that they are parametric adaptive. The filter with six sections is practically realized in the Laboratory for Modeling, Simulation and Control Systems. Performances of the designed filter are proved on modeling and identification of the system for differential pulse code modulation. Real response and response from the proposed filter are compared with regard to the chosen criteria function. Also, a comparative analysis of the proposed filter with some existing filters is performed
Production of traditional meat products in small and micro establishments in Serbia: current status and future perspectives
The production of traditional meat products has a considerable potential in the Republic of Serbia, particularly in small and micro (household) establishments. Among a large number of traditional meat products, dry fermented sausages and dried meat products are the most important and commonly appreciated by consumers. There is, however, a need for a better standardization of the production in this meat sector, and also implementation of necessary food hygiene rules and HACCP principles according to hygiene regulations. There are provisions in the Food Safety Law, stating the principles of flexibility, which would allow for traditional meat producers and their associations to apply for derogations in food hygiene regulations. This would enable traditional small and micro food business operators to better use their resources, relax administrative burden and use traditional production methods in the most appropriate manner, always respecting hygiene and safety principals. This review paper analyses the current status of traditional meat production in small and micro establishments in Serbia, emphasizing a need for further improvements in food safety management and standardization
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