Analysis of the life insurance market in the Republic of Macedonia

Life insurance in the Republic of Macedonia has a short history, if we do not count the experience of ZOIL Makedonija before the independence of Republic of Macedonia. The recent history of life insurance covers the last seven years and the segment of life insurance comprises about 6% of the total insurance market in the Republic of Macedonia. In this paper we analyse the development of life insurance in the Republic of Macedonia in recent history, taking the gross premiums of two of the best companies that are working in the segment of life insurance. Besides analysing the influence of the basic determinants of the development of life insurance (GDP, monetary stability, social insurance, etc.) we analyse the model of time series, with the purpose of making a model and forecasting future values of the series

SPECIES IDENTIFICATION FOR AQUATIC BIOMONITORING USING DEEP RESIDUAL CNN AND TRANSFER LEARNING

Aquatic insects and other benthic macroinvertebrates are mostly used as bioindicators of the ecological status of freshwaters. However, an expensive and time-consuming process of species identification represents one of the key obstacles for reliable biomonitoring of aquatic ecosystems. In this paper, we proposed a deep learning (DL) based method for species identification that we evaluated on several available public datasets (FIN-Benthic, STONEFLY9, and EPT29) along with our Chironomidae dataset (CHIRO10). The proposed method relies on three DL techniques used to improve robustness when training is done on a relatively small dataset: transfer learning, data augmentation, and feature dropout. We applied transfer learning by employing ResNet-50 deep convolutional neural network (CNN) pretrained on ImageNet 2012 dataset. The results show significant improvement compared to original contributions and confirms that there is a considerable gain when there are multiple images per specimen

Oxidation behavior during prolonged service of boiler tubes made of 2.25Cr1Mo and 12Cr1Mo0.3V heat resistance steels

During service of thermal power plant (TPP) units, different components are exposed to high temperature due to technological cycle of TPP unit. Service lifetimes of these components, especially boiler heating surfaces, may be limited due to creep, fatigue or oxidation, but materials designed for use at high temperatures have been developed primarily for their creep properties and microstructural stability during long term exposures at elevated temperatures. Having in mind that oxidation in steam environment on the inner surface of boiler tubes and in flue gass on the outer surface of boler tubes could lead to a different consequences regarding service life of tubes, either directly through metal wastage or indirectly through raising local temperatures due to the lower thermal conductivity of the oxide scale, the oxidation behaviour of a different heat resistant steels become very important characteristics. In this paper are presented some data about the oxidation behavior of boiler tubes made of 2.25Cr1Mo and 12Cr1Mo0.3V steel after service of approximately 130.000 and 200.000h in two 620MVV TPP units. Characterization of oxide scales on the inner side on tubes made of two steels with different chromium content, after two different prolonged periods of service, were compared and also their influence on the service life of tubes and kinetics of oxide scale growth were analyzed

Oxidation behavior during prolonged service of boiler tubes made of 2.25Cr1Mo and 12Cr1Mo0.3V heat resistance steels

During service of thermal power plant (TPP) units, different components are exposed to high temperature due to technological cycle of TPP unit. Service lifetimes of these components, especially boiler heating surfaces, may be limited due to creep, fatigue or oxidation, but materials designed for use at high temperatures have been developed primarily for their creep properties and microstructural stability during long term exposures at elevated temperatures. Having in mind that oxidation in steam environment on the inner surface of boiler tubes and in flue gass on the outer surface of boler tubes could lead to a different consequences regarding service life of tubes, either directly through metal wastage or indirectly through raising local temperatures due to the lower thermal conductivity of the oxide scale, the oxidation behaviour of a different heat resistant steels become very important characteristics. In this paper are presented some data about the oxidation behavior of boiler tubes made of 2.25Cr1Mo and 12Cr1Mo0.3V steel after service of approximately 130.000 and 200.000h in two 620MVV TPP units. Characterization of oxide scales on the inner side on tubes made of two steels with different chromium content, after two different prolonged periods of service, were compared and also their influence on the service life of tubes and kinetics of oxide scale growth were analyzed

Oxidation behavior during prolonged service of boiler tubes made of 2.25Cr1Mo and 12Cr1Mo0.3V heat resistance steels

During service of thermal power plant (TPP) units, different components are exposed to high temperature due to technological cycle of TPP unit. Service lifetimes of these components, especially boiler heating surfaces, may be limited due to creep, fatigue or oxidation, but materials designed for use at high temperatures have been developed primarily for their creep properties and microstructural stability during long term exposures at elevated temperatures. Having in mind that oxidation in steam environment on the inner surface of boiler tubes and in flue gass on the outer surface of boler tubes could lead to a different consequences regarding service life of tubes, either directly through metal wastage or indirectly through raising local temperatures due to the lower thermal conductivity of the oxide scale, the oxidation behaviour of a different heat resistant steels become very important characteristics. In this paper are presented some data about the oxidation behavior of boiler tubes made of 2.25Cr1Mo and 12Cr1Mo0.3V steel after service of approximately 130.000 and 200.000h in two 620MVV TPP units. Characterization of oxide scales on the inner side on tubes made of two steels with different chromium content, after two different prolonged periods of service, were compared and also their influence on the service life of tubes and kinetics of oxide scale growth were analyzed

Influence of plasma transferred arc welding parameters on the obtained microstructure of 316L coating

The paper describes the surfacing technology for coating of high-alloyed austenitic stainless steel 316L on the steel S235JR base material. Coatings were applied by plasma transferred arc welding process. The 5 samples were made using different welding currents while other welding param-eters were constant. Metallographic analysis of the obtained samples is used to establish a correlation between the micro-structural constituents and the applied welding current in the surfacing process. According to this it was possible to determine the optimal parameters of coating surfacing. The filler material was in the form of powder, while its charac-terization was performed by scanning electron microscopy, and the characterization of the obtained coatings by optical microscopy. © 2023 Society for Structural Integrity and Life (DIVK). All rights reserved.Ovaj rad opisuje tehnologiju navarivanja prevlake od visokolegiranog austenitnog nerđajućeg čelika 316L na osnovni materijal od čelika S235JR. Prevlaka je nanesena tehnikom navarivanja plazmom. Izrađeno je 5 epruveta sa različitim vrednostima jačine struje, dok su ostali parametri navarivanja bili konstantni. Metalografska analiza dobijenih epruveta je iskorišćena za uspostavljanje korelacije između mikrostrukture i jačine struje tokom procesa navarivanja. Na osnovu toga je bilo moguće odrediti optimalne parametre za navarivanje. Korišćen je dodati materijal u obliku praha i njegova karakterizacija je izvršena uz pomoć skenirajućeg elektronskog mikroskopa, dok je karakterizacija samog navarenog sloja urađena primenom optičkog mikroskopa.This paper was presented at the Second International Symposium on Risk Analysis and Safety of Complex Structures and Components (IRAS 2023), 2-4 April 2023, Belgrade, Serbi

Influence of plasma transferred arc welding parameters on the obtained microstructure of 316L coating

The paper describes the surfacing technology for coating of high-alloyed austenitic stainless steel 316L on the steel S235JR base material. Coatings were applied by plasma transferred arc welding process. The 5 samples were made using different welding currents while other welding param¬eters were constant. Metallographic analysis of the obtained samples is used to establish a correlation between the micro¬structural constituents and the applied welding current in the surfacing process. According to this it was possible to determine the optimal parameters of coating surfacing. The filler material was in the form of powder, while its charac¬terization was performed by scanning electron microscopy, and the characterization of the obtained coatings by optical microscopy

Formalization of Human Categorization Process Using Interpolative Boolean Algebra

Since the ancient times, it has been assumed that categorization has the basic form of classical sets. This implies that the categorization process rests on the Boolean laws. In the second half of the twentieth century, the classical theory has been challenged in cognitive science. According to the prototype theory, objects belong to categories with intensities, while humans categorize objects by comparing them to prototypes of relevant categories. Such categorization process is governed by the principles of perceived world structure and cognitive economy. Approaching the prototype theory by using truth-functional fuzzy logic has been harshly criticized due to not satisfying the complementation laws. In this paper, the prototype theory is approached by using structure-functional fuzzy logic, the interpolative Boolean algebra. The proposed formalism is within the Boolean frame. Categories are represented as fuzzy sets of objects, while comparisons between objects and prototypes are formalized by using Boolean consistent fuzzy relations. Such relations are directly constructed from a Boolean consistent fuzzy partial order relation, which is treated by Boolean implication. The introduced formalism secures the principles of categorization showing that Boolean laws are fundamental in the categorization process. For illustration purposes, the artificial cognitive system which mimics human categorization activity is proposed