In-Depth Performance Analysis of SMOTE-Based Oversampling Algorithms in Binary Classification

In the field of machine learning, the problem of class imbalance considerably impairs the performance of classification algorithms. Various techniques have been proposed that seek to mitigate classifier bias with respect to the majority class, with simple oversampling approaches being one of the most effective. Their main representative is the well-known SMOTE algorithm, which introduces a synthetic instances creation mechanism as an interpolation procedure between minority instances. To date, an abundance of SMOTE-based extensions that intend to improve the original algorithm has been proposed. This paper aims to compare the performance of several such extensions. In addition to comparing the overall performance, the impact of the selected oversamplers on the per-class performance is also evaluated. Finally, this paper tries to interpret the obtained performance results with respect to the internal procedures of oversampling algorithms. Some interesting findings have been made in this regard

Osnivanje montipne jedrilice namjenjene jednodnevnim čartert izletima i natjecanjima

Cilj ovog diplomskog rada je prikazati idejnu izradu svih dijelova monotipne charter jedrilice namijenjene za dnevne izlete i natjecanja. Jedrilica je opremljena pomičnom kobilicom kojoj gaz varira od 1,8 do 0,8 m dubine što joj omogućuje plovidbu i plitkim vodama. Jedrilica se također može iznajmljivati za jednodnevne izlete ali i za regate što je bitno za popunu kapaciteta u „mtrvoj sezoni“. Kako je jedrilica izrađena i kakve su joj mogućnosti pročitajte u ovom diplomskom radu

Optimizacija modela LAN/MAN mreže temeljena na eksperimentalnim mjerenjima

MAN design includes elements of LAN and WAN design. A model of MAN design presented in this paper describes a methodological approach to MAN modeling and necessity for single link optimization and link system optimization in case of common communication link sharing. MAN optimization methods are presented using experimental MAN made in IEEE 802.11g technology and a point-to-multipoint operation mode where wireless links share a common communication medium. Results of measurements confirm the influence of communication media sharing as well as the size and the number of packets and a hierarchical MAN network model on MAN throughput.Dizajn MAN-a uključuje elemente LAN i WAN mreža. Model dizajna MAN-a predstavljen ovim radom opisuje metodološki pristup modeliranju MAN-a i potrebu za optimizacijom pojedinačnog linka kao i sustava poveznica u slučaju dijeljenja zajedničkog komunikacijskog medija. Metode optimizacije MAN-a predstavljene su na primjeru eksperimentalne MAN mreže izgrađene IEEE 802.11g tehnologijom u načinu rada točka-više točaka u kojemu bežične poveznice dijele zajednički komunikacijski medij. Rezultati mjerenja potvrđuju utjecaj dijeljenja zajedničkog komunikacijskog medija, veličine i broja paketa te hijerarhijskog modela mreže na propusnost MAN-a

Efficient parallel implementations of approximation algorithms for guarding 1.5D terrains

In the 1.5D terrain guarding problem, an x-monotone polygonal line is dened by k vertices and a G set of terrain points, i.e. guards, and a N set of terrain points which guards are to observe (guard). This involves a weighted version of the guarding problem where guards G have weights. The goal is to determine a minimum weight subset of G to cover all the points in N, including a version where points from N have demands. Furthermore, another goal is to determine the smallest subset of G, such that every point in N is observed by the required number of guards. Both problems are NP-hard and have a factor 5 approximation [3, 4]. This paper will show that if the (1+ϵ)-approximate solver for the corresponding linear program is a computer, for any ϵ > 0, an extra 1+ϵ factor will appear in the final approximation factor for both problems. A comparison will be carried out the parallel implementation based on GPU and CPU threads with the Gurobi solver, leading to the conclusion that the respective algorithm outperforms the Gurobi solver on large and dense inputs typically by one order of magnitude

Performance evaluation of windows virtual machines on a Linux host

Virtualization has experienced a dramatic expansion recently and today is ubiquitous in modern IT industry since it provides numerous benefits to companies and individual users. It increases efficiency, flexibility and scalability of IT equipment by enabling different software-based environments on a single physical hardware. Each virtual machine is a separate instance that is completely independent and separated from the computer hardware and it runs on emulated hardware. Emulated hardware is managed by virtualization tool that provides lower resources when compared to physical hardware. This paper presents a performance evaluation of three different virtual machines run by three recent versions of Windows operating system, namely Windows 7TM Professional, Windows 8.1TM Professional and Windows 10TM Professional, on a host computer system run by Linux Ubuntu. Performance measurement results show that Window 7 is the most suitable virtual operating system since it obtains the best performance when run on a Linux host

Pregled potencijalnih primjena, koristi i rizika od nanosenzora i nanotehnologija u hrani

Usage of nanotechnology in food with all of its possible different applications has potential to significantly change today’s ways of food manufacturing and packaging as well as to alter fundamental functionality of food. Application of nanotechnology in food increases food safety, allows better delivery of new functional ingredients and extends product life. Food nanotechnology implies nanotechnology application in food package manufacturing and nanotechnology application directly to food products. Production of nanopackages implies usage of nanosensors for detection of contaminants and pathogens, nanosensors for product tracking and control, nanoparticles for improvement of mechanical properties and biodisintegration of a package. New food ingredients in food can be delivered by means of colloids, liposomes, nanoemulsions or nanolaminats, thus transforming food products into health preparation or a medicine. Increased research in the field of nanofood application and a possible nanofood mass production can perhaps lead to health risk for consumers; hence it is important to pass new scientifically based regulations which will define usage of food nanotechnology.Upotreba nanotehnologije u području hrane sa svojim mogućim raznovrsnim primjenama ima mogućnost da uvelike promijeni ne samo dosadašnji način proizvodnje i pakiranja već transporiranja i čuvanja hrane. Upotrebom nanotehnologija u hrani povećava se sigurnost hrane, omogućuje kvalitetnija dostava novih funkcionalnih sastojaka pomoću hrane, te produljuje vijek trajanja proizvoda. Pod pojmom nanotehnologije u hrani podrazumijeva se primjena nanotehnologija u proizvodnji pakovina za hranu i primjena nanotehnologija izravno na prehrambene proizvode. U proizvodnji nanopakovina upotrebljavaju se nanosenzori za detekciju patogena i kontaminanata, nanosenzori za sljedivost i kontrolu proizvoda, nanočestice za poboljšavanje mehaničkih svojstava i biorazgradivosti pakovine, te nanočestice antibakterijskih svojstava. Dostava novih sastojaka u hranu obavlja se pomoću koloida, liposoma, nanoemulzija ili nanolaminata čime prehrambeni proizvod postaje zdravstveni preparat ili lijek. Povećanje istraživanja primjene nanohrane nose sa sobom i moguće opasnosti od uzimanja nanohrane po zdravlje potrošača, te će se morati donijeti znanstveno utemeljeni propisi koji će definirati upotrebu nanotehnologija u hrani

Bolja spektralna iskoristivost linka za višestruke kapacitete koji pokazuju prometnu međuovisnost

Network providers need very effective optimization tool for good utilization of scarce link capacities during exploitation. In the case of multiple link capacities with mutual traffic correlation such problem could be more demanding. The sizing problem is explained for satellite link, but it could be applicable for other transmission resources. Dimensioning of getaway link (G-link) can be realized only by new constructions (new channel equipment) on the Earth side. Mathematical model for optimal capacity sizing of N different link elements (capacity types) is explained, minimizing the total cost (expansion, conversion and maintenance). Instead of nonlinear convex optimization technique, that could be very exhausting, the network optimization method is applied. With such approach an efficient heuristic algorithm for three different capacity types is being developed. Through numerical test-examples this approach shows the significant complexity savings, but giving us very close to optimal result. However, in real circumstances some adding limitations on capacity state values have to be introduced. In comparison to other options it is obvious that heuristic option M_H (with only one negative value per capacity state) shows the best ratio between complexity reduction and result deterioration.Mrežni operateri nužno trebaju vrlo efikasan optimizacijski alat za učinkovito iskorištenje oskudnih kapaciteta na prijenosnim linkovima kroz određeno eksploatacijsko razdoblje. U slučaju višestrukih kapaciteta, a koji pokazuju prometnu međuovisnost, takav problem postaje još složeniji. Članak se koncentrira na probleme satelitskog linka, ali je primjenjiv i za neke druge prijenosne kapacitete. Proširenje G-linka može se ostvariti samo uvođenjem nove kanalske opreme na Zemlji. U radu je prikazan matematički model za optimalno dimenzioniranje linka sa N različitih kapacitivnih elemenata, s ciljem minimiziranja troškova ekspanzije, konverzije i održavanja kanalske opreme. Umjesto nelinearnog konveksnog programiranja, a koje može biti vrlo iscrpljujuće, primjenjuje se metoda mrežne optimizacije. Potom je razvijen i testiran heuristički algoritam za tri vrste kapaciteta. Algoritam pokazuje visoku učinkovitost, a nerijetko postiže i najbolji mogući rezultat, pri čemu se značajno smanjuje složenost. Ipak u realnim uvjetima uvode se dodatna ograničenja na vrijednosti kapacitivnih točaka, pa govorimo o algoritamskim varijantama. Algoritamska varijanta M_H (samo jedna negativna vrijednost po kapacitivnoj točki) pokazuje najbolji odnos između kompleksnosti algoritma i odstupanja od najboljeg mogućeg rezultata, odnosno pogrješke

Analysis and Proposals for Improving Knowledge and Skills in Engineering Aimed at Reducing Unemployment

The aim of this paper is to assess the readiness of engineering students to enter the labour market and to make proposals for improving their knowledge and skills. Our research is based on the assumption that smart economic growth should be based on interdisciplinary knowledge including ICT, communication in foreign languages and economic knowledge. Results of the study conducted on a sample of 153 final-year engineering students point to the necessity of changing educational needs, and to the knowledge and skills desirable in the labour market, and this is supported by the respondents’ opinion on the conditions for knowledge acquisition at their tertiary education institutions but also by their willingness to acquire the necessary knowledge

Social entrepreneurial intentions and motivational drivers among business students

Purpose: The paper is aimed at determining young people\u27s motives and views related to entrepreneurship, in particular social entrepreneurship. To this purpose, a survey was conducted at the School of Economics and Business in Sarajevo to explore the motivations of the student population to pursue entrepreneurship, with a focus on social entrepreneurship and their intentions to engage in it. The survey examined socio-political, situational and personal factors and their direct and mediating effect on the intention to engage in social entrepreneurship. Methodology: The research model and methodology presented in the paper are based on the process theory of motivation and the model used by Barton et al. (2018) and by Krueger (1993). The model elaborated by this paper’s authors is expanded and redefined so as to take account of socio-political factors and the respondents’ views of them. Results: The research revealed a limiting and de-stimulating effect of environmental factors on the intention to start a business, as well as the significance of situational and personal factors when deciding on engaging in social entrepreneurship. Conclusion: The conducted research revealed that young people in Bosnia and Herzegovina understand the significance of social entrepreneurship for society at large, as well as for themselves, i.e. the sense of fulfilment it could bring. The results could suggest that, for the respondents, the desirable entrepreneurial option would be the one that implies involvement not in the social entrepreneurship but in the socially responsible entrepreneurship

Optimization Methods in Modern Transportation Systems

One of the greatest challenges in the public transportation network is the optimization of the passengers waiting time, where it is necessary to find a compromise between the satisfaction of the passengers and the requirements of the transport companies. This paper presents a detailed review of the available literature dealing with the problem of passenger transport in order to optimize the passenger waiting time at the station and to meet the requirements of companies (maximize profits or minimize cost). After a detailed discussion, the paper clarifies the most important objectives in solving a timetabling problem: the requirements and satisfaction of passengers, passenger waiting time and capacity of vehicles. At the end, the appropriate algorithms for solving the set of optimization models are presented