Online communities – Designing Usability, Supporting Sociability

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How Does Intellectual Capital Affect the Financial Performance of Micro, Small, and Medium-Sized Hotel Companies?

Theoretical background: Intellectual capital is often considered a critical resource, especially for micro, small, and medium-sized, as well as service companies. Human, structural, and relational capital are often listed as the main components of intellectual capital. This study complements the studies on the impact of intellectual capital and its components on the financial performance of hotel companies in developing economies. Purpose of the article: The study aims to examine the impact of the efficiency of intellectual capital and its components on the financial performance of micro, small, and medium-sized hotel companies in Serbia. The results of the study can be of importance for hotel managers in their efforts to make adequate business decisions and improve the financial performance of hotel companies. Research methods: The sample includes 100 micro, small, and medium-sized hotel companies from Serbia with the highest operating revenues in 2019. The efficiency of the intellectual capital and its components is measured by using the modified value-added intellectual coefficient (MVAIC). Financial performance is measured by using the natural logarithm of earnings before interest, taxes, depreciation, and amortization (EBITDA), EBITDA margin, return on assets (ROA) and return on equity (ROE). Ordinary least squares regression is used to examine the impact of intellectual capital and its components on the financial performance of sample hotel companies from 2015 to 2019. Main findings: The results of the study show that intellectual capital efficiency has a positive impact on all four measures of financial performance. They also show that structural capital has the greatest impact on financial performance and that only this component of intellectual capital has a positive impact on all four measures of financial performance. Capital employed has a positive impact on the natural logarithm of EBITDA and ROE, while human capital has a positive impact on the EBITDA margin and a negative on the natural logarithm of EBITDA. Relational capital has a positive impact only on ROA

Nitroso-Oxidative Stress, Acute Phase Response, and Cytogenetic Damage in Wistar Rats Treated with Adrenaline

This study is aimed at analysing biochemical and genetic endpoints of toxic effects after administration of adrenaline. For this purpose, the study was carried out on Wistar rats and three doses of adrenaline were used: 0.75 mg/kg, 1.5 mg/kg, and 3 mg/kg body weight. To achieve these aims, we investigated the effects of adrenaline on catalase (CAT), Cu, Zn-superoxide dismutase (SOD), malondialdehyde (MDA), nitrite (NO2-), carbonyl groups (PCC), and nitrotyrosine (3-NT). Total activity of lactate dehydrogenase (LDH), its relative distribution (LDH1-LDH5) activity, level of acute phase proteins (APPs), and genotoxic effect were also evaluated. The obtained results revealed that all doses of adrenaline induced a significant rise in CAT activity, MDA level, PCC, NO2-, and 3-NT and a significant decrease in SOD activity compared to control. Adrenaline exerted an increase in total activity of LDH, LDH1, and LDH2 isoenzymes. Further study showed that adrenaline significantly decreased serum albumin level and albumin-globulin ratio, while the level of APPs (alpha(1) -acid glycoprotein and haptoglobulin) is increased. The micronucleus test revealed a genotoxic effect of adrenaline at higher concentrations (1.5 mg/kg and 3 mg/kg body weight) compared to untreated rats. It can be concluded that adrenaline exerts oxidative and nitrative stress in rats, increased damage to lipids and proteins, and damage of cardiomyocytes and cytogenetic damage. Obtained results may contribute to better understanding of the toxicity of adrenaline with aims to preventing its harmful effects

Genetic diversity of the autochtonous Phaseolus bean germplasm originating from five South east European countries

Genetic differentiation of 167 Phaseolus vulgaris L. accessions originating from five South east European countries was performed using 13 SSR markers. Analysis included 21 accessions from Bosnia and Herzegovina, 15 accessions from Croatia, 73 accessions from Macedonia, 38 accessions from Serbia and 20 accessions from Slovenia. Calculated mean number of alleles per locus was 9.8. The average polymorphic information content over all loci reached value of 0.710 where the most informative locus was GATS91 (0.926). These results showed that selected set of SSR markers are highly informative and applicable for studies of genetic diversity within germplasm collected in the five South east European countries, which was also confirmed with the calculated value of probability of identity (1.831x10). High mean value of expected heterozygosity (0.731) and Shannon’s information index (1.486) reflects high genetic diversity within accessions from five countries, where accessions from Macedonia are genetically the most uniform, due to 17completely identical accessions included

Scheduling School Activities Using Evolutionary Computation

Problemi izrade rasporeda nastavnih aktivnosti sveprisutni su i izrazito važni na svim obrazovnim institucijama. Prema računalnoj složenosti ovi problemi uobičajeno pripadaju u razred NP-teških problema. U znanstvenoj literaturi obrađuje se nekoliko pojednostavljenih verzija problema; međutim, u praksi je broj problema koje je potrebno riješiti znatno veći. Stoga je u okviru ovog rada dan pregled većeg skupa problema raspoređivanja nastavnih aktivnosti. Za svaki od problema dan je formalni model te odgovarajući optimizacijski problem. Dodatno su razmotreni različiti zahtjevi koji se još postavljaju na konačna rješenja te način njihove ugradnje u optimizacijski problem. Zbog svoje složenosti, najčešći se problemi raspoređivanja nastavnih aktivnosti ne mogu rješavati iscrpnom pretragom kao niti jednostavnim heuristikama. U okviru ovog rada postavljena je hipoteza da su algoritmi odnosno metaheuristike evolucijskog računanja prikladne za rješavanje svih prethodno formalno definiranih problema raspoređivanja. Hipoteza je provjerena izradom niza metaheurističkih algoritama i provjerom njihove sposobnosti rješavanja stvarnih primjera. Razmotreni su načini paralelizacije ovih algoritama, počev od problemski specifičnih. Ostvaren je i hibridni paralelni algoritam evolucijskog računanja. Definiran je formalni model sustava za potporu procesima raspoređivanja koji omogućava objavu napravljenih rasporeda te provođenje analiza zauzeća korisnika. Temeljem tog modela izgrađen je programski sustav čiji je rad ispitan u praksi.Problems of scheduling of school activities are ubiquitous and extremely important to all educational institutions. According to the computational complexity of these problems they usually belong to the class of NP-hard problems. The scientific literature usually deals with simplified versions of several such problems. However, in practice, a number of problems that needs to be solved is much larger. In this thesis therefore an overview of a larger set of scheduling problems of school activities is given. For each problem a formal model is determined and an associated optimization problem is given. In addition, a various requirements are described that are usually additionally placed on the final schedule as well as the technique for its inclusion in optimization problem. Because of complexity, the most common scheduling problems of school activities can not be solved by means of exhaustive search nor simple heuristics. In this thesis, we hypothesize that the evolutionary computation algorithms / metaheuristics are suitable for solving all previously formally defined scheduling problems. Hypothesis was verified by creating a series metaheuristics algorithms and checking their ability to solve real-world problem instances. In this thesis the parallelization of these algorithms is also researched, starting from problem-specific paralelization techniques. Also, the parallel hybrid evolutionary computation algorithm is described. Finally, a formal model of the system is described which offers the support for publishing results of scheduling and which allows conducting the analysis of users business. Based on this model, a software system was built and tested in practice

Model of e-examination system with support for intelligent assessment management

U radu je dan kratak uvod u sustave e-učenja, i trenutno važeće norme na ovom području. Potom je ukratko analizirana potpora e-ispitivanju poznatih sustava WebCT i MOODLE, kao i prethodno razvijenog sustava WODLS. Dan je i kratak osvrt na sustav Nescume, koji se koristi za pristup sustavu e-ispitivanja StudTest. Uveden je model sustava StudTest, i definirani su osnovni koncepti tog modela. Ukratko je opisana uloga definiranih koncepata i njihov međusobni odnos. Definiran je i način interakcije između pojedinih implementacija koncepata odgovarajućih modela. Razrađena je mogućnost uporabe definiranih koncepata za izvedbu sustava koji omogućava inteligentno (ili prilagodljivo) vođenje ispitnog procesa. Ilustrirano je što treba napraviti i na koji način, kako bi se pružila ovakva usluga. Opisana je prototipna implementacija sustava e-ispitivanja zasnovana na modelu StudTest. Opisana je i korištena tehnologija te razlozi njene uporabe, kao i konkretna implementacija koncepata samog modela. Potom su ilustrirane mogućnosti razvijenog sustava kroz niz razvijenih zadataka, uz kratke komentare o njihovim mogućnostima, načinu postavljanja pitanja i načinu vrednovanja studentovih odgovora. Iznesen je kritički osvrt na razvijeni model, njegove karakteristike, način primjene sustava u stvarnoj nastavi te postignuti rezultati. Rad sadrži i dodatak s većim dijelom zadataka razvijenih za potrebe kolegija Digitalna logika.In this work a short introduction to e-learning systems and current relevant standards is given. E-examination support of recognized systems WebCT and MOODLE is analyzed, as well as of previously developed system WODLS. A short description of Nescume system, which is used for accessing e-examination system StudTest, is presented. StudTest model and relevant concepts, such as prlets, are then defined. A short description of defined concepts is given, as well as their relationship. Interaction among defined concepts is also defined. A way for using defined concepts for intelligent (or adaptive) assessment management is described. Then, it is illustrated what must be done, in order to provide this service. A prototype implementation of e-examination system is described, based on StudTest model. Also, used technology and reasons for its usage is elaborated, as well as the implementation of model concepts. Then, capabilities of developed system are illustrated, through a series of developed prlets, along with comments on their capabilities, on the way of asking questions and on techniques of answer correctness evaluation. A critical review of developed model, its characteristics, usage in education process and results are given. This work also contains an appendix, with most of prlets developed for course Digital logic

Scheduling School Activities Using Evolutionary Computation

Problemi izrade rasporeda nastavnih aktivnosti sveprisutni su i izrazito važni na svim obrazovnim institucijama. Prema računalnoj složenosti ovi problemi uobičajeno pripadaju u razred NP-teških problema. U znanstvenoj literaturi obrađuje se nekoliko pojednostavljenih verzija problema; međutim, u praksi je broj problema koje je potrebno riješiti znatno veći. Stoga je u okviru ovog rada dan pregled većeg skupa problema raspoređivanja nastavnih aktivnosti. Za svaki od problema dan je formalni model te odgovarajući optimizacijski problem. Dodatno su razmotreni različiti zahtjevi koji se još postavljaju na konačna rješenja te način njihove ugradnje u optimizacijski problem. Zbog svoje složenosti, najčešći se problemi raspoređivanja nastavnih aktivnosti ne mogu rješavati iscrpnom pretragom kao niti jednostavnim heuristikama. U okviru ovog rada postavljena je hipoteza da su algoritmi odnosno metaheuristike evolucijskog računanja prikladne za rješavanje svih prethodno formalno definiranih problema raspoređivanja. Hipoteza je provjerena izradom niza metaheurističkih algoritama i provjerom njihove sposobnosti rješavanja stvarnih primjera. Razmotreni su načini paralelizacije ovih algoritama, počev od problemski specifičnih. Ostvaren je i hibridni paralelni algoritam evolucijskog računanja. Definiran je formalni model sustava za potporu procesima raspoređivanja koji omogućava objavu napravljenih rasporeda te provođenje analiza zauzeća korisnika. Temeljem tog modela izgrađen je programski sustav čiji je rad ispitan u praksi.Problems of scheduling of school activities are ubiquitous and extremely important to all educational institutions. According to the computational complexity of these problems they usually belong to the class of NP-hard problems. The scientific literature usually deals with simplified versions of several such problems. However, in practice, a number of problems that needs to be solved is much larger. In this thesis therefore an overview of a larger set of scheduling problems of school activities is given. For each problem a formal model is determined and an associated optimization problem is given. In addition, a various requirements are described that are usually additionally placed on the final schedule as well as the technique for its inclusion in optimization problem. Because of complexity, the most common scheduling problems of school activities can not be solved by means of exhaustive search nor simple heuristics. In this thesis, we hypothesize that the evolutionary computation algorithms / metaheuristics are suitable for solving all previously formally defined scheduling problems. Hypothesis was verified by creating a series metaheuristics algorithms and checking their ability to solve real-world problem instances. In this thesis the parallelization of these algorithms is also researched, starting from problem-specific paralelization techniques. Also, the parallel hybrid evolutionary computation algorithm is described. Finally, a formal model of the system is described which offers the support for publishing results of scheduling and which allows conducting the analysis of users business. Based on this model, a software system was built and tested in practice

Steel pedestrian bridge – main tin girder : Master's Thesis

Prema zadanim gabaritima napravljen je projekt konstrukcije čeličnog mosta. Na temelju zadanih gabarita, napravljen je prostorni proračunski model čelične metalne konstrukcije na kojemu je izvršeno dimenzioniranje svih nosivih elemenata. Nakon toga napravljeno je oblikovanje konstrukcije, proračun priključaka te je izrađena radionička dokumentacija metalne konstrukcije pomoću računalnog programa Autocad 2013. Na kraju su dati iskazi materijala pojedinih elemenata i ukupne količine materijala potrebne za izgradnju čeličnog pješačkog mosta.Based on given dimensions was made the project of construction of steel bridge. Also, on the given dimensions was made spatial design model of steel metal construction on which was made dimensioning of load - bearing elements. After that was made design of construction, estimate of connections and was made workshop documentation of metal construction using computer program Autocad 2013. In the end are given statements of material of individual elements and the total quantity of material what is required for building pedestrian metal bridge

Scheduling School Activities Using Evolutionary Computation

Problemi izrade rasporeda nastavnih aktivnosti sveprisutni su i izrazito važni na svim obrazovnim institucijama. Prema računalnoj složenosti ovi problemi uobičajeno pripadaju u razred NP-teških problema. U znanstvenoj literaturi obrađuje se nekoliko pojednostavljenih verzija problema; međutim, u praksi je broj problema koje je potrebno riješiti znatno veći. Stoga je u okviru ovog rada dan pregled većeg skupa problema raspoređivanja nastavnih aktivnosti. Za svaki od problema dan je formalni model te odgovarajući optimizacijski problem. Dodatno su razmotreni različiti zahtjevi koji se još postavljaju na konačna rješenja te način njihove ugradnje u optimizacijski problem. Zbog svoje složenosti, najčešći se problemi raspoređivanja nastavnih aktivnosti ne mogu rješavati iscrpnom pretragom kao niti jednostavnim heuristikama. U okviru ovog rada postavljena je hipoteza da su algoritmi odnosno metaheuristike evolucijskog računanja prikladne za rješavanje svih prethodno formalno definiranih problema raspoređivanja. Hipoteza je provjerena izradom niza metaheurističkih algoritama i provjerom njihove sposobnosti rješavanja stvarnih primjera. Razmotreni su načini paralelizacije ovih algoritama, počev od problemski specifičnih. Ostvaren je i hibridni paralelni algoritam evolucijskog računanja. Definiran je formalni model sustava za potporu procesima raspoređivanja koji omogućava objavu napravljenih rasporeda te provođenje analiza zauzeća korisnika. Temeljem tog modela izgrađen je programski sustav čiji je rad ispitan u praksi.Problems of scheduling of school activities are ubiquitous and extremely important to all educational institutions. According to the computational complexity of these problems they usually belong to the class of NP-hard problems. The scientific literature usually deals with simplified versions of several such problems. However, in practice, a number of problems that needs to be solved is much larger. In this thesis therefore an overview of a larger set of scheduling problems of school activities is given. For each problem a formal model is determined and an associated optimization problem is given. In addition, a various requirements are described that are usually additionally placed on the final schedule as well as the technique for its inclusion in optimization problem. Because of complexity, the most common scheduling problems of school activities can not be solved by means of exhaustive search nor simple heuristics. In this thesis, we hypothesize that the evolutionary computation algorithms / metaheuristics are suitable for solving all previously formally defined scheduling problems. Hypothesis was verified by creating a series metaheuristics algorithms and checking their ability to solve real-world problem instances. In this thesis the parallelization of these algorithms is also researched, starting from problem-specific paralelization techniques. Also, the parallel hybrid evolutionary computation algorithm is described. Finally, a formal model of the system is described which offers the support for publishing results of scheduling and which allows conducting the analysis of users business. Based on this model, a software system was built and tested in practice

Steel pedestrian bridge – main tin girder : Master's Thesis

Prema zadanim gabaritima napravljen je projekt konstrukcije čeličnog mosta. Na temelju zadanih gabarita, napravljen je prostorni proračunski model čelične metalne konstrukcije na kojemu je izvršeno dimenzioniranje svih nosivih elemenata. Nakon toga napravljeno je oblikovanje konstrukcije, proračun priključaka te je izrađena radionička dokumentacija metalne konstrukcije pomoću računalnog programa Autocad 2013. Na kraju su dati iskazi materijala pojedinih elemenata i ukupne količine materijala potrebne za izgradnju čeličnog pješačkog mosta.Based on given dimensions was made the project of construction of steel bridge. Also, on the given dimensions was made spatial design model of steel metal construction on which was made dimensioning of load - bearing elements. After that was made design of construction, estimate of connections and was made workshop documentation of metal construction using computer program Autocad 2013. In the end are given statements of material of individual elements and the total quantity of material what is required for building pedestrian metal bridge