Document representations for classification of short web-page descriptions

Motivated by applying Text Categorization to classification of Web search results, this paper describes an extensive experimental study of the impact of bag-of- words document representations on the performance of five major classifiers - Naïve Bayes, SVM, Voted Perceptron, kNN and C4.5. The texts, representing short Web-page descriptions sorted into a large hierarchy of topics, are taken from the dmoz Open Directory Web-page ontology, and classifiers are trained to automatically determine the topics which may be relevant to a previously unseen Web-page. Different transformations of input data: stemming, normalization, logtf and idf, together with dimensionality reduction, are found to have a statistically significant improving or degrading effect on classification performance measured by classical metrics - accuracy, precision, recall, F1 and F2. The emphasis of the study is not on determining the best document representation which corresponds to each classifier, but rather on describing the effects of every individual transformation on classification, together with their mutual relationships.

ICT Technologies in Optimization of Machines Movement at Open-Pit Coal Mine

Auxiliary machinery is used at the open-pit coal mine (machines: bulldozers, trench excavators, pipe-laying machines, ...) for performance of auxiliary work (excavation, construction of route, ....) in order to provide an uninterrupted operation of the basic machinery for excavation of waste rock and coal. Machines are moving from one area of the open-pit to another. Movement of machines along the open-pit is limited space-wise by conveyor belts serving for conveyance of waste rocks and coal, including other natural obstructions (steep slopes, mud, water). These obstructions affect the open-pit machines' length of trajectory, duration of movement and consumption of fuel. Observing the said problem, a model for optimizing the "movement" of open-pit auxiliary machinery has been developed and applied with ICT, namely GPS/GPRS and appropriate software solution, as presented herein. Model determines the "shortest" path of the machine to the job which can result in significant fuel savings and reducing failures of machines

Momčilo Spremić, Србија и Венеција (VI–XVI век) [Srbija i Venecija (6.-16. st.)], Službeni glasnik, Beograd 2014., 340 str.

Prikaz knjige

Momčilo Spremić, Србија и Венеција (VI–XVI век) [Srbija i Venecija (6.-16. st.)], Službeni glasnik, Beograd 2014., 340 str.

Prikaz knjige

Mihajlo St. Popović, Од Будима до Константинопоља: Via Traiana у светлу путописне литературе у периоду од 14. до 16. века [Od Budima do Konstantinopola: Via Traiana u svijetlu putopisne literature u periodu od 14. do 16. stoljeća], prevela s njemačkog Branka Rajlić, Akademska knjiga, Novi Sad 2017., 194 str.

Prikaz knjige

A Phenotypic Point of View of the Adaptive Radiation of Crested Newts (Triturus cristatus Superspecies, Caudata, Amphibia)

The divergence in phenotype and habitat preference within the crested newt Triturus cristatus superspecies, examined across different ontogenetic stages, provides an excellent setting to explore the pattern of adaptive radiation. The crested newts form a well-supported monophyletic clade for which at least the full mitochondrial DNA phylogeny is resolved. Here we summarise studies that explored the variation in morphological (larval and adult body form, limb skeleton, and skull shape) and other phenotypic traits (early life history, developmental sequences, larval growth rate, and sexual dimorphism) to infer the magnitude and direction of evolutionary changes in crested newts. The phenotypic traits show a high level of concordance in the pattern of variation; there is a cline-like variation, from T. dobrogicus, via T. cristatus, T. carnifex, and T. macedonicus to the T. karelinii group. This pattern matches the cline of ecological preferences; T. dobrogicus is relatively aquatic, followed by T. cristatus. T. macedonicus, T. carnifex, and the T. karelinii group are relatively terrestrial. The observed pattern indicates that phenotypic diversification in crested newts emerged due to an evolutionary switch in ecological preferences. Furthermore, the pattern indicates that heterochronic changes, or changes in the timing and rate of development, underlie the observed phenotypic evolutionary diversification

Optimizing the performance of optimization in the cloud environment–An intelligent auto-scaling approach

The cloud computing paradigm has gained wide acceptance in the scientific community, taking a significant share from fields previously reserved exclusively for High Performance Computing (HPC). On-demand access to a large amount of computing resources provided by Cloud makes it ideal for executing large-scale optimizations using evolutionary algorithms without the need for owning any computing infrastructure. In this regard, we extended WoBinGO, an existing parallel software framework for genetic algorithm based optimization, to be used in Cloud. With these extensions, the framework is capable of elastically and frugally utilizing the underlying cloud computing infrastructure for performing computationally expensive fitness evaluations. We studied two issues that are pertinent when dealing with large-scale optimization in the elastic cloud environment: the computing instance launching overhead and the price of engaging Cloud for solving optimization problems, in terms of the instances’ cumulative uptime. To explain the usability limits of WoBinGO framework running in the IaaS environment, a comprehensive analysis of the framework’s performance was given. Optimization of both total optimization time and total cumulative uptime, leads to minimizing the cost of cloud resources utilization. In this way, we are proposing an intelligent decision support engine based on artificial neural networks and metaheuristics to provide the user with an assessment of the framework’s behavior on the underlying infrastructure in terms of optimization duration and the cost of resource consumption. According to a given assessment, the user can decide upon faster delivery of results or lower infrastructure costs. The proposed software framework has been used to solve a complex real-world optimization problem of a subsurface rock mass model calibration. The results obtained from the private OpenStack deployment show that by using the proposed decision support engine, significant savings can be achieved in both optimization time and optimization cost

Ekonomska efektivnost mehanizovnog ubiranja kamilice

Chamomile as a medicinal and aromatic plant is very important as a valuable product in the world market of medicinal plants. Regardless of that, there have been only a few researches so far concerning economic effects of its production. Costs of chamomile harvesting require special attention as these costs, as a rule, account for a major portion in the structure of total costs. The aim of this paper is to show when it is economically justified to substitute hand harvesting by machine harvesting as well as to determine the largest possible investment in purchasing different harvesters for chamomile harvesting. For that purpose were used enterprise budgeting (analytical calculations) of chamomile production, calculations of costs of agricultural machinery, as well as dynamic methods for investment evaluation (present value method). It was determined that it is economically justified to substitute hand harvesting with mechanized harvesting of chamomile on land area of over 2.5, i.e. 4 ha of chamomile, depending on the harvester type. If harvesters are used on land areas smaller than this economical effectiveness of the investments in purchasing them, i.e. their present value, depends on the harvester type and the land area on which chamomile is grown.Kamilica kao lekovita i aromatična vrsta je od velikog značaja, jer predstavlja značajan artikal na svetskom tržištu lekovitog bilja. Bez obzira na to, do sada postoji samo mali broj istraživanja koja se odnose na ekonomske efekte njene proizvodnje. Posebnu pažnju kod gajenja kamilice treba obratiti na troškove ubiranja, koji po pravilu imaju najveće učešće u strukturi ukupnih troškova. Cilj ovog rada je da utvrdi kada je ekonomski opravdano preći sa ručnog na mašinsko ubiranje kamilice i koliko se najviše može investirati u nabavku različitih kombajna za berbu kamilice. Da bi se to proverilo, korišćene su analitičke kalkulacije proizvodnje kamilice, kalkulacije rada poljoprivrednih mašina, kao i dinamičke metode za ocenu investicija (metod prinosne vrednosti). Utvrđeno je da je ekonomski opravdano preći sa ručnog na mehanizovano ubiranje kamilice na površinama koje prelaze 2,5 odnosno 4 ha kamilice, zavisno od tipa kombajna. Ako se kombajni koriste na površinama manjim od prethodno navedenih, ekonomska efektivnost investicija u njihovu nabavku, odnosno visina njihove prinosne vrednosti, zavisi od tipa kombajna i površine na kojoj se gaji kamilica