Analysis of Radar Doppler Signature from Human Data

This paper presents the results of time (autocorrelation) and time-frequency (spectrogram) analyses of radar signals returned from the moving human targets. When a radar signal falls on the human target which is moving toward or away from the radar, the signals reflected from different parts of his body produce a Doppler shift that is proportional to the velocity of those parts. Moving parts of the body causes the characteristic Doppler signature. The main contribution comes from the torso which causes the central Doppler frequency of target. The motion of arms and legs induces modulation on the returned radar signal and generates sidebands around the central Doppler frequency, referred to as micro-Doppler signatures. Through analyses on experimental data it was demonstrated that the human motion signature extraction is better using spectrogram. While the central Doppler frequency can be determined using the autocorrelation and the spectrogram, the extraction of the fundamental cadence frequency using the autocorrelation is unreliable when the target is in the clutter presence. It was shown that the fundamental cadence frequency increases with increasing dynamic movement of people and simultaneously the possibility of its extraction is proportional to the degree of synchronization movements of persons in the group

New data on distribution and ecology of Batrachospermum (Rhodophyta) in Serbia

The paper describes the distribution and ecology of populations of the genus Batrachospermum collected in Serbia from 2006 to 2015 at 10 sites, all of which represent new localities of Batrachospermum in Serbia. The records of this genus in the Boračka River and in a spring near Kragujevac (Cerovac) are the first in Central Serbia. Batrachospermum was recorded at altitudes of from 235 to 1600 m at localities mainly in partial or full shade on stone, gravel or concrete substrata in cold water (10.50 - 15.40oC) that was neutral to weakly alkaline (pH 7.2 – 8.65) with conductivity of from 55 to 539 μS/cm. Species of the genus Batrachospermum in Serbia have to date been recorded in clean, well-aerated waters with a low concentration of biogenic salts and in habitats without anthropogenic impact. Any factors altering abiotic parameters of their habitats can lead to changes and the loss of populations of the sensitive species of this genus

Discourses on domestic violence and narratives of women victims of partners' violence

Nasilje u porodici se u savremenom društvu smatra jednim od najtežih oblika nasilja jer se njegovim ispoljavanjem krše osnovna ljudska prava i slobode članova porodice. Međutim, značenje nasilja u porodici može se konstruisati na različite načine u različitim diskursima. Cilj ovog rada je istraživanje konstruisanja značenja nasilja u porodici u pravnom i medijskom diksursu i u narativima žena žrtava partnerskog nasilja. Teorijsko utemeljenje ovog istraživanja predstavlja socijalni konstrukcionizam, Fukoovo razumevanje diskursa, odnosa moć/znanje i subjekta i feminističko razumevanje nasilja nad ženama u porodici. Istraživački pristup problemu je kvalitativan i podrazumeva upotrebu analize sadržaja, diskurzivnu analizu i narativnu analizu. Analiza pravnog diskursa ukazuje na konstrukcionističku prirodu fenomena nasilja u porodici što se ilustruje praćenjem promena u definisanju značenja nasilja u porodici u različitim pravnim dokumentima. Analizom su obuhvaćeni određeni članovi zakona u kojima se definiše značenje nasilja u porodici (Zakon o javnom redu i miru iz 1994. godine, Zakon o izmenama i dopunama Krivičnog zakona iz 2002. godine, Krivični zakonik iz 2005. godine, Porodični zakon iz 2005. godine) i Nacionalna strategija za sprečavanje i suzbijanje nasilja nad ženama u porodici i u partnerskim odnosima, usvojena 2011. godine. Sprovedena analiza pokazuje promenu u značenju nasilja u porodici tokom posmatranih godina. Promene u označavanju se konstruišu promenom u značenju nasilnog postupka koji će se smatrati nasilnim, promenom označavanja posledica koje takvo nasilje izaziva i promenom označavanja članova porodice na koje se usvojeni zakoni odnose. Analiza medijskog diskursa podrazumevala je analizu novinskih članaka u dnevnim novinama Blic i Politika u 2003, 2007. i 2011. godini. Analizom je obuhvaćeno 432 novinska članka o nasilju u porodici...In modern society domestic violence is considered as one of the worst forms of violence because its manifestations violate basic human rights and freedom of family members. However, the meaning of domestic violence can be constructed in different ways through different discourses. The aim of this work is to explore constructing meanings of domestic violence in legal and media discourses and in narratives of women victims of partners’ violence. The theoretical foundation of this research is social constructionism, Foucault's understanding of discourse, his understanding of the relation between power / knowledge and the subject, as well as the feminist understanding of domestic violence against women. The research is based on the qualitative approach to the problem which implies the use of content analysis, discourse analysis and narrative analysis. The law discourse analysis indicates the constructionist nature of the phenomenon of domestic violence, as it is illustrated by tracking the change in the meaning of domestic violence in different legal documents. The analysis refers to some articles of the Serbian national laws which define the meaning of domestic violence (Law on Public Peace and Order – 1994; The Law on Amendments to the Criminal Law – 2002; Criminal Code – 2005; Family Law - 2005) and to National Strategy for preventing and combating domestic and partners’ violence against women, adopted 2011. The conducted analysis shows a change in the meaning of domestic violence during these years. Changes in labeling of domestic violence are constructed by changing the meaning of actions that would be considered as violent, by changing labeling of consequences caused by such violence, as well as by changing labeling of family members to which these laws apply. The analysis of media discourse entailed an analysis of newspaper articles edited in daily newspapers Blic and Politika during 2003, 2007 and 2011. The analysis included 432 newspapers articles on domestic violence..

Analysis of the capacity changes in the 'Garajevac-Istok' excavation by applying the GIS technology

The paper discusses the concept of construction and monitoring of capacity changes - the volume of the "Garajevac-Istok" excavation (mine), located in the cadastral municipality of Novi Bečej. Namely, in the earlier period, the physical surface of the Earth and geospace in general were shown two-dimensionally (2D), in a plane, by some of the cartographic methods (contour lines, points heights, hypsometry) or three-dimensionally (3D), by modeling of reliefs and relief cards. The cartographic principles of terrain making and visualizing on relief mapping models allow the creation of 3D views, but not enough quality and engineering precise 3D terrain models. In addition, there is a possibility of quantitative and qualitative assessment of the terrain on the mentioned models not to be accurate enough. With new technologies, the 3D geospatial display mode changes, and the concept of digital terrain modeling (DTM) is being applied. The main goal of the work is to create 3D models and to give an analysis of the "Garajevac-Istok" mine for a certain period of exploitationU radu se razmatra koncept izrade i praćenja promena kapaciteta - kubature kopa 'Garajevac - istok', koji se nalazi na katastarskoj opštini Novi Bečej. Ranije su se fizička površ Zemlje i geoprostor uopšte prikazivali dvodimenzionalno (2D) u ravni, nekom od kartografskih metoda (izolinije, kote, hipsoskala) ili trodimenzionalno (3D), izradom maketa i reljefnih karata. Kartografski principi izrade i vizualizacije terena na reljefnim kartografskim modelima omogućuju stvaranje 3D prikaza, ali ne i dovoljno kvalitetnog i inženjerski preciznog 3D modela terena. Pritom je mogućnost kvantitativne i kvalitativne ocene terena na pomenutim modelima otežan i nije dovoljno tačan. Sa pojavom novih tehnologija menja se način 3D prikaza geoprostora, odnosno primenjuje se koncept izrade digitalnih modela terena (DMT). Osnovni cilj rada jeste kreiranje 3D modela i uporedna analiza kubature kopa 'Garajevac - istok' za određeni period eksploatacije

ǂThe ǂcivil wars in the Byzantine historiography of 14. and 15. century

У оквиру ове докторске дисертације проучавали смо начин на који су ромејски историчари XIV и XV столећа посматали и описивали унутрашње сукобе у Византијском царству. Наиме, имајући на уму ко су били ти историчари, када су писали своја дела и из којих побуда, проучавали смо њихово схватање ових конфликата самих по себи, затим њихово виђење узрока и повода, као и последица који су они оставили за собом. Поред тога, такође смо се дотакли питања да ли је реченим сукобима византијска историографија можда придавала и неку врсту социјалне димензије, а уједно, где је тако нешто било могуће, осврнули смо се и на њено виђење грађанских ратова као феномена. Највише закључака могли смо извући у вези сукоба описаних у делима Нићифора Григоре и Јована Кантакузина, који су били не само њихови савременици, па чак и учесници, већ су и своје списе практично посветили тим превирањима. Нажалост, када је реч о оним конфликтима где смо били приморани да се ослањамо искључиво на дела тзв. историчара пада, то јест Лаоника Халкокондила, Дуке и Георгија Сфранциса, наше могућности биле су неупоредиво суженије. Због свега тога, разуме се да на свако од горепоменутих питања није било увек могуће пружити јасан одговор или је тако нешто било могуће само посредно, што нарочито важи за сукобе који су се одиграли у последњим деценијама постојања Византијског царства. Штавише, за неке од тих конфликата, за које је добро познато у историјској науци да су се збили, конкретно оне из 1385. и 1390. године, није било чак могуће доћи до било каквих закључака, будући да их ромејска историографија уопште ни не спомиње. С тим у вези, желели бисмо такође да истакнемо да смо наше закључке, па чак и претпоставке, заснивали пре свега на речима самих византијских историчара, које смо преведене на српски језик и постављене у одговарајући контекст, цитирали на страницама овог рада. Том приликом, посебну пажњу смо посветили и анализи грчких термина и синтагми које су они употребљавали, што је било од особите важности за проучавање њихове перцепције тих сукоба. Усудили би смо се да кажемо да је један од скромних доприноса ове наше студије било и само превођење места које садрже такве речи, не само због тога што нека од њих нису преведена не само на српски, па чак ни на друге савремене језике, већ је и због тога што је неколица њих занимљива за српску историју...In this doctoral dissertation we have been studing the manner in which the Byzantine historians of the 14th and 15th centuries, were observing and describing the internal conflicts that were taking place in their Empire. Namely, bearing in mind who were these historians, when they were writing their works and for which motives, we have been analyzing their perception of these conflicts, the understanding of their reasons, causes and consequences, as well as, whether they were attributing to them in generally (or some of them) a some kind of social dimension. In same time, whenever was possible, we were also referring to their comprehension of a civil war as a phenomenon. The most of conclusions, we could draw about those conflicts described by Nicephorus Gregoras and John Cantacuzenus, who were not only their contemporaries and even participiants, but also practically dedicated their historical writings to them. Unfortunately, in the case of the conflicts narrated exclusively by the so-called Historians of the Fall, that is, Laonicus Chalcocondyles, Ducas and George Sphrantzes, our possibilities were incomparably narrower. Therefore, it was not always possible to give a precise answer on each of the aforementioned questions (or something like that was possible only in indirect manner), especially for those conflicts that took place in the last decades of the existence of the Byzantine Empire. Moreover, for some of them (i.e. those of 1385 and 1390) it was not possible to draw any kind of conclusion, since the Byzantine historiography doesn᾽t mentions them at all. In this respect, we would like to point out that our conclusions, and even assumptions, were based primarily on the words of the Byzantine historians themselves, which we have quoted on the pages of this study, translated into Serbian language and placed in the appropriate context. In such occasions, we have paid a special attention to analyzing of the Greek terms and phrases used by the Byzantine historians, the fact that was of the particular importance for the study of their perceptions of these conflicts. We would dare to say that one of the modest contributions of the our work to the historical science was the translation of the places that contain such words, not only because some of them were not translated neither into Serbian, nor in some other modern languages, but also because several of them are interesting and for Serbian history..

Tribological Aspects of the Process of Winding the Steel Rope Around the Winch Drum

Proper winding of the steel rope around the winch drum is great importance, mostly for: prolonging the service life of the rope, reduction of deformations of the body and the sides of the drum if the winding of the rope is multilayered, increasing of the safety factors, easier unwinding of the rope while lowering the load, even running of the drive unit, etc. The focus of this paper is on the analysis of the friction which occurs in the process of winding and unwinding the rope around the winch drum. Friction force is in its highest intensity when the rope passes from one layer to another, if the winding of the rope is multilayered. As the result of the research, certain mechanisms of winding of the rope from the aspects of the friction force were obtained, and the effects of the forces on the sides of the drum were analyzed

Fractional Calculus Model of Electrical Impedance Applied to Human Skin

Fractional calculus is a mathematical approach dealing with derivatives and integrals of arbitrary and complex orders. Therefore, it adds a new dimension to understand and describe basic nature and behavior of complex systems in an improved way. Here we use the fractional calculus for modeling electrical properties of biological systems. We derived a new class of generalized models for electrical impedance and applied them to human skin by experimental data fitting. The primary model introduces new generalizations of: 1) Weyl fractional derivative operator, 2) Cole equation, and 3) Constant Phase Element (CPE). These generalizations were described by the novel equation which presented parameter (beta) related to remnant memory and corrected four essential parameters (R-0, R-infinity, alpha, tau(alpha)). We further generalized single generalized element by introducing specific partial sum of Maclaurin series determined by parameters (beta(*), gamma,delta ...). We defined individual primary model elements and their serial combination models by the appropriate equations and electrical schemes. Cole equation is a special case of our generalized class of models for beta* = gamma = delta = ... = 0. Previous bioimpedance data analyses of living systems using basic Cole and serial Cole models show significant imprecisions. Our new class of models considerably improves the quality of fitting, evaluated by mean square errors, for bioimpedance data obtained from human skin. Our models with new parameters presented in specific partial sum of Maclaurin series also extend representation, understanding and description of complex systems electrical properties in terms of remnant memory effects

Modeling of bioimpedance for human skin based on fractional distributed-order modified cole model

Eksperimentalni podaci otpornosti i računa necelobrojnog reda koriste se za modeliranje bioimpedansnih osobina ljudske kože. Uveli smo i predložili modifikovani Kole model koristeći pri tom operator distribuiranog necelog reda koji je zasnovan na Caputo-Weyl-ovim izvodima necelog reda.Naš predloženi model predstavlja izmenjen jedno-disperzijski Kole model, jer uvodi nove parametre k i σ u jedno-disperzijskoj Kole impedansnoj jednačini. Ovi parametri karakterišu širinu intervala oko frakcionog indeksa α i oni su važni za precizniji opis bioimpedansnih osobina ljudske kože. Predloženi modifikovani Kole model mnogo bolje daje fitovanje date eksperimentalne krive u datom frekventnom opsegu u poređenju sa sa postojećim Kole modelima. Fitovanje je urađeno primenom Levenberg-Marquardt algoritma nelinearnih najmanjih kvadrata.Electrical impedance measurement data and fractional calculus have been utilized for modeling bioimpedance properties of human skin. We introduced and proposed revisited Cole model using modified distributed order operator based on the Caputo-Weyl fractional derivatives. Our proposed model presents essentially modified single-dispersion Cole model, since it introduces a new parameters k and σ in single-dispersion Cole impedance equation. These parameters characterize the width of interval around fractional index α and they are important for more accurate describing bioimpedance properties of human skin. The impedance spectrum was measured in a finite frequency range up to 100 kHz. Our proposed modified Cole model fits much better to experimental curve in a given frequency range compared to existing Cole models. The fitting is done using the Levenberg-Marquardt nonlinear least squares