Radovan Radovanović

The manuscript proposes a new non-linear and non-stationary bivariate stochastic model, termed the two-dimensional Gaussian (generalized) Split-BREAK (2D-GSB) process, as a multivariate extension of the univariate GSB framework. The generalization consists in introducing a common threshold mechanism based on the norm of a bivariate innovation vector and a single synchronized Bernoulli indicator which jointly governs regime activation in both components. This structure induces cross-dependent regime shifts and yields a binomial–Gaussian mixture representation of the joint distribution, explicitly linking contemporaneous dependence with a common latent regime mechanism. The fundamental properties of the proposed model are established, with particular emphasis on its asymptotic behavior. Parameter estimation procedure is developed using both the method of moments (MoM) and the empirical characteristic function (ECF) approach, and their performance is evaluated through Monte Carlo simulations. An empirical application to daily crime data illustrates how the proposed framework captures synchronized structural shocks and heavy-tailed features in related crime categories. In comparison with a standard VAR(1) benchmark, the 2D-GSB specification provides a parsimonious yet substantially improved likelihood-based fit, thus offering a theoretically sound framework for analyzing multivariate time series characterized by synchronized regime shifts and heavy-tailed behavior.

Ovaj rad prikazuje eksperimentalnu analizu produkata sagorevanja različitih građevinskih materijala u prisustvu dizel goriva kao akceleratora, primenom masene spektrometrije. Ispitivani su uzorci cigle, laminata, tepisona, tarketa i vinila. Sagorevanje uz dodatak dizel goriva rezultovalo je pojavom karakterističnih masenih obrazaca akceleratora, sa dominantnim signalima u oblastima m/z 43 i 57, kao i u višem masenom opsegu m/z 69–71 i m/z 91, koji se mogu dovesti u vezu sa fragmentacijom alifatskih i aromatskih komponenti dizel goriva. Primenom diferencijalne analize masenih spektara omogućeno je izdvajanje signala koji potiču od produkata sagorevanja u prisustvu akceleratora, uz efikasno uklanjanje uticaja atmosferskih gasova. Posebno je uzeto u obzir da detektovani signali potiču od neutralnih vrsta uzorkovanih iz gasne faze, koje se jonizuju unutar masenog spektrometra. Dobijeni rezultati pokazuju da kombinacija masene spektrometrije i diferencijalne analize predstavlja pouzdan pristup za identifikaciju prisustva dizel goriva u složenim požarnim ostacima.

Moderni pristupi spasavanju integrišu naprednu tehnologiju, specijalizovanu obuku i međunarodnu saradnju kako bi povećali efikasnost i smanjili rizike za spasioce. Ključne tehnologije uključuju dronove, robote opremljene senzorima, termalne kamere i softver za analizu stabilnosti ruševina. Obuka spasilaca obuhvata tehničke veštine, rad sa psima tragačima i pružanje osnovne psihološke podrške. Međunarodni standardi, kao što su INSARAG, omogućavaju bolju koordinaciju i interoperabilnost između timova. Prevencija se postiže kroz obrazovanje građana, poboljšanje sistema za rano upozoravanje i promociju gradnje otporne na zemljotrese. Veštačka inteligencija dodatno pomaže u analizi podataka i prepoznavanju obrazaca kako bi se identifikovala prisutnost preživelih. Ovi pristupi ne samo da ubrzavaju proces spasavanja, već i značajno doprinose bezbednosti i pripravnosti zajednica za potencijalne prirodne katastrofe.

The manuscript deals with solving a mathematical model of criminal activities (MCA model), in order to facilitate the understanding of the dynamics of crime and implement certain measures in its prevention and deterrence. For the MCA model, consists of two coupled ordinary differential equations of the diffusion type, the stability and existence of a unique Cauchy solution are first examined. Thereafter, coupled equations of the MCA model are transformed into a dimensionless system on the unit interval and solved using the homotopy perturbation method (HPM). In this way, recursive sequences of approximate HPM solutions are obtained and, under certain conditions, their convergence has been proven. In the following, using different initial conditions, several numerical simulations of the proposed HPM technique in solving MCA model were conducted, as well as a practical application of the proposed procedure in modeling real-world crime rate data.

Information is the primary driver of progress in today’s world, especially given the vast amounts of data available for extracting meaningful knowledge. The motivation for addressing the problem of forensic analysis—specifically the validity of decision making in multi-criteria contexts—stems from its limited coverage in the existing literature. Methodologically, machine learning and ensemble models represent key trends in this domain. Datasets used for such purposes can be either real or synthetic, with synthetic data becoming particularly valuable when real data is unavailable, in line with the growing use of publicly available Internet data. The integration of these two premises forms the central challenge addressed in this paper. The proposed solution is a three-layer ensemble model: the first layer employs multi-criteria decision-making methods; the second layer implements multiple machine learning algorithms through an optimized asymmetric procedure; and the third layer applies a voting mechanism for final decision making. The model is applied and evaluated through a case study analyzing the U.S. Army’s decision to replace the Colt 1911 pistol with the Beretta 92. The results demonstrate superior performance compared to state-of-the-art models, offering a promising approach to forensic decision analysis, especially in data-scarce environments.

From the first use of nuclear weapons in the battlefield to the present day, eight decades have passed. Due to its destructive power, this type of weapon has never been used in warfare again. However, the fear that this weapon will be used again has never disappeared. On the contrary, all states possessing this type of armament have not abandoned it but have modernized it to such an extent that it seems that just one wrong move by a statesman could bring this world to the brink of extinction. This paper systematically reviews knowledge about nuclear weapons and classifies them according to various criteria. Throughout history, there have been various efforts to abolish this weapon, and with the development of different types of nuclear armaments, new agreements have emerged aiming to reduce specific types of projectiles. The paper demonstrates the impact of these agreements on the signatories and the reduction of certain types of weapons.

U radu se analizira internet inteligentnih uređaja tehničke bezbednosti u ustanovama za izvršenje krivičnih sankcija u podršci procesu odlučivanja u bezbednosno incidentnim situacijama. Ustanove za izvršenje krivičnih sankcija po svojoj funkciji su mesta sa visokim rizikom od bezbednosno incidentnih situacija. Inteligentni uređaji tehničke bezbednosti su strukturisani u uređaje za video nadzor i perimetrijsku zaštitu, uređaje za održavanje veze, uređaje za otkrivanje i prepoznavanje nedozvoljenih metalnih predmeta, sisteme za kontrolu pristupa i idetifikaciju, sisteme detekcije požara i sisteme mehaničke zaštite, čijom integracijom sistem tehničke bezbednosti čini funkionalnu celinu. Integracija ovih sistema treba da pomogne strategijskom i top nivou bezbednosnog menadžmenta u procesu odlučivanja u uslovima bezbednosno incidentnih situacija.

Овим радом представљене су најсавременије методе у анализирању узорака земљишта: рендгенско - флуоресцентни спектрометар за детекцију олова и уређај за рендгенску дифракцију за детекцију минерала хидроцерусита. Укратко ће бити објашњени основни параметри везани за чауре, пројектиле, барутне честице и земљиште. Затим се наводи утицај чаура, пројектила и барутних честица на земљиште услед њиховог распадања и таложења. На крају се истиче потенцијална употреба ових података за развој нове методе за упоредну форензичку анализу трагова. Циљ овог истраживачког рада је да укаже на важност проналажења нових метода за упоредну форензичку анализу трагова. Анализе ће показати на који начин резултати доприносе ефикаснијем раду форензичара у расветљењу дела противних закону

The modern age brings daily changes in the safe environment and new security risks for protected values, which creates the need for the engagement of all security subjects and resources at their disposal, so as to successfully combat new forms of crime. The private security sector has experienced a large-scale expansion with the development of society, and this development is directly related to the security requirements of clients to effectively respond to the increasing challenges in suppressing and controlling crime and threats to the safety of persons, property and business. In order to adequately respond to security risks and to prepare security officers for timely identification of the said risks and proper response to them, the Law on Private Security defined the licensing of both legal and natural persons. The subject matter and the goal of this research is to indicate the importance of licensing in the field of private security with a critical review thereof given the time lapse since the implementation of the aforementioned legal provisions and experience from practice. The authors also wanted this paper to point out some of the problems and shortcomings related to the licensing process itself, which occur in practice, based on the experiential conclusions.