Commutators in Completely Simple Semigroups

We obtain a characterization of the binary commutator on completely simple semigroups, using their Rees matrix representation. Consequently, we prove that a regular semigroup is nilpotent (solvable) if and only if it is simple, and all its $\mathcal{H}$-classes are nilpotent (solvable) groups

Primena vodećih indikatora u analizi i predviđanju ekonomske aktivnosti Srbije

The paper presents the search for the possibilities of using the leading indicators in analyzing and forecasting the economic activity in Serbia. The leading indicators for Serbia have not been identified so far. This is why the research of possibilities of their use required considering some important theoretical and methodological issues related to the cyclical analysis of the economic activity in Serbia and identification of the cyclical indicators. These issues are as follows: the general approach to cyclical analysis, the choice of a reference series and the choice of the appropriate methodology for identification of leading indicators. As an appropriate general approach to cyclical analysis the growth cycles approach has been considered. As the reference series the monthly GDP is used. The monthly GDP has been interpolated starting with officially available quarterly data and using Boot, Feibes and Lisman (BFL) method of temporal disaggregation. The trend has been estimated using HP filter. Starting from the general approach to cyclical analysis, the methodology of OECD has been proposed as the appropriate for identification of leading indicators for Serbia. The methodology of OECD is presented and the possibilities of using that methodology for Serbia have been considered. Finally, the possibilities of using the leading indicators in Serbia have been researched.Rad istražuje mogućnosti primene vodećih indikatora u analizi i predviđanju ekonomske aktivnosti Srbije. Vodeći indikatori za Srbiju još uvek nisu identifikovani, tako da je ispitivanje mogućnosti primene vodećih indikatora zahtevalo razmatranje određenih teorijskih i metodoloških pitanja koja su u vezi sa cikličnom analizom ekonomske aktivnosti Srbije i identifikacijom vodećih indikatora. Ova pitanja bila su: razmatranje opšteg pristupa cikličnoj analizi, izbor referentne serije, izbor odgovarajuće metodologije za identifikaciju vodećih indikatora. Kao odgovarajući opšti pristup cikličnoj analizi ekonomske aktivnosti, određen je pristup ciklusa rasta. Kao referentna serija u radu je korišćen mesečni bruto domaći proizvod, koji je dobijen vremenskom dezagregacijom zvanično raspoloživih kvartalnih podataka za bruto domaći proizvod na osnovu BFL metoda (Boot-Feibes-Lisman) vremenske dezagregacije vremenskih serija, pri čemu je za identifikaciju trenda korišćen HP (Hodrick-Prescott) filter. Polazeći od opšteg pristupa cikličnoj analizi, kao odgovarajuća metodologija za identifikaciju vodećih indikatora za Srbiju, predložena je metodologija OECD-a. Predstavljena je metodologija OECD-a i razmotrene su mogućnosti primene ove metodologije za Srbiju. Na kraju, istražene su mogućnosti primene vodećih indikatora za Srbiju

A new virtual team competence defining model

Virtual team members need to acquire specific competencies to ensure team success. In line with this, by establishing standards for selection the virtual team members can provide their successful performance that achieves organisational goals. The article focuses on a variety of factors that affect the professional competencies in virtual teams. It also suggests models for measuring such competencies. The authors also present an example of how the model may be applied. Namely, in case study this article focuses upon the capacities of a virtual organisation to form the project team the members of which will come from a virtual university, on the basis of knowledge and collaboration. Conclusion and recommendation are made for further research and improvements in this area

Izbor kriterijuma za odlučivanje u uslovima rizika

Normative decision theory has developed a large number of decision-making criteria that may be used in the decision-making process in circumstances of risk. How to choose the adequate one for the given problem situation? The choice of an adequate decision making criterion requires the knowledge of criteria, their features, and the possibility of their utilization in different situations. In this study, a criteria analysis is also suggested, from the aspect of consistency with the aim to be achieved and with the features of the decision problem, from the aspect of ability to achieve rationality and from the point of view of the acceptability of consequences the change of the criterion will produce. The requirements set upon the decision-maker by the normative theory in the aspect of respecting axioms for rational choice and the maximization principle are also presented. The criteria analysis requires the usage of the results of the descriptive decision theory research as well, which, due to the bounded rationality of the decision-maker, questions the abilities of the criterion to keep to the axioms of rationality and provide maximization.Normativna teorija odlučivanja razvila je veliki broj kriterijuma koji se mogu koristiti u procesu odlučivanja u uslovima rizika. Kako među njima odabrati odgovarajući kriterijum za odlučivanje u datoj problemskoj situaciji? Izbor odgovarajućeg kriterijuma zahtevaće poznavanje kriterijuma za odlučivanje, njihovih karakteristika i mogućnosti primene u različitim situacijama odlučivanja. U radu se, takođe, predlaže i analiza kriterijuma s aspekta konzistentnosti sa ciljem koji se želi postići i karakteristikama problemske situacije, s aspekta mogućnosti postizanja racionalnosti, kao i sa stanovišta prihvatljivosti posledica koje će primena kriterijuma izazvati. Izloženi su i zahtevi koje normativna teorija postavlja donosiocu odluka u vezi sa poštovanjem aksioma racionalnog izbora i principa maksimizacije. Analiza kriterijuma zahtevaće korišćenje i rezultata istraživanja deskriptivne teorije odlučivanja, koja, usled ograničene racionalnosti donosioca odluke, dovodi u pitanje mogućnosti kriterijuma da se do kraja ispoštuju aksiomi racionalnosti i obezbedi maksimizacija

The use of information and communication technologies by enterprises in the European Union member countries

The paper analyzes the use of information and communication technologies (ICT) in enterprises in the European Union member states. The objectives of the analysis were to examine the level reached in the application of ICT in European enterprises and explore the differences in ICT usage that exist between the EU member states. The analysis is based on the Eurostat data on ICT usage in enterprises in the European Union countries (EU-28) for the years 2018 and 2017. The following indicators of ICT usage were analyzed: fixed broadband access, the speed of the internet connections, the presence of the Internet (enterprises having a website), the use of social media, the use of cloud computing services, e-commerce indicators (the share of the enterprises making e-sales and the share of e-commerce in the total turnover) and the indicators of e-business integration - the share of the enterprises using enterprise resource planning (ERP), customer relationship management (CRM) and the supply chain management (SCM) software applications. A comparative analysis of the EU countries by the value of these indicators was carried out. The main focus in the analysis was to identify the factors that influence the difference in the value of the ICT indicators between the countries. The analysis has shown that the regional position, the geographic characteristics, the size of the country and the level of its economic development are the factors that influence these differences.U radu se analizira primena informaciono-komunikacionih tehnologija (IKT) u preduzećima u zemljama članicama Evropske unije (EU). Ciljevi analize bili su da se ispita dostignuti nivo u primeni IKT u preduzećima i da se istraže razlike u korišćenju IKT koje postoje među zemljama članicama EU. U analizi su korišćeni podaci EUROSTAT-a o primeni IKT u preduzećima Evropske unije (EU-28) za 2017. i 2018. Analizirani su sledeći indikatori primene IKT u preduzećima: širokopojasna internet konekcija, brzina internet konekcije, prisustvo na internetu (posedovanje Web sajta), korišćenje društvenih medija, korišćenje cloud računarstva, indikatori e-trgovine (udeo preduzeća koja prodaju svoje proizvode preko interneta i učešće e-trgovine u ukupnom prometu), i indikatori integrisanosti e-poslovanja (udeo preduzeća koja koriste integralni poslovni software, software za upravljanje odnosima sa klijentima i softver za upravljanje lancem snabdevanja). Izvršena je komparativna analiza zemalja EU po vrednosti ovih indikatora, sa ciljem da se utvrdi koji faktori utiču na razlike u vrednosti indikatora među zemljama. Analiza je pokazala da su regionalni položaj, geografske karakteristike, veličina zemlje i dostignut nivo ekonomskog razvoja faktori koji utiču na ove razlike

The use of information and communication technologies by enterprises in the European Union member countries

The paper analyzes the use of information and communication technologies (ICT) in enterprises in the European Union member states. The objectives of the analysis were to examine the level reached in the application of ICT in European enterprises and explore the differences in ICT usage that exist between the EU member states. The analysis is based on the Eurostat data on ICT usage in enterprises in the European Union countries (EU-28) for the years 2018 and 2017. The following indicators of ICT usage were analyzed: fixed broadband access, the speed of the internet connections, the presence of the Internet (enterprises having a website), the use of social media, the use of cloud computing services, e-commerce indicators (the share of the enterprises making e-sales and the share of e-commerce in the total turnover) and the indicators of e-business integration - the share of the enterprises using enterprise resource planning (ERP), customer relationship management (CRM) and the supply chain management (SCM) software applications. A comparative analysis of the EU countries by the value of these indicators was carried out. The main focus in the analysis was to identify the factors that influence the difference in the value of the ICT indicators between the countries. The analysis has shown that the regional position, the geographic characteristics, the size of the country and the level of its economic development are the factors that influence these differences.U radu se analizira primena informaciono-komunikacionih tehnologija (IKT) u preduzećima u zemljama članicama Evropske unije (EU). Ciljevi analize bili su da se ispita dostignuti nivo u primeni IKT u preduzećima i da se istraže razlike u korišćenju IKT koje postoje među zemljama članicama EU. U analizi su korišćeni podaci EUROSTAT-a o primeni IKT u preduzećima Evropske unije (EU-28) za 2017. i 2018. Analizirani su sledeći indikatori primene IKT u preduzećima: širokopojasna internet konekcija, brzina internet konekcije, prisustvo na internetu (posedovanje Web sajta), korišćenje društvenih medija, korišćenje cloud računarstva, indikatori e-trgovine (udeo preduzeća koja prodaju svoje proizvode preko interneta i učešće e-trgovine u ukupnom prometu), i indikatori integrisanosti e-poslovanja (udeo preduzeća koja koriste integralni poslovni software, software za upravljanje odnosima sa klijentima i softver za upravljanje lancem snabdevanja). Izvršena je komparativna analiza zemalja EU po vrednosti ovih indikatora, sa ciljem da se utvrdi koji faktori utiču na razlike u vrednosti indikatora među zemljama. Analiza je pokazala da su regionalni položaj, geografske karakteristike, veličina zemlje i dostignut nivo ekonomskog razvoja faktori koji utiču na ove razlike

The use of information and communication technologies by enterprises in the European Union member countries

The paper analyzes the use of information and communication technologies (ICT) in enterprises in the European Union member states. The objectives of the analysis were to examine the level reached in the application of ICT in European enterprises and explore the differences in ICT usage that exist between the EU member states. The analysis is based on the Eurostat data on ICT usage in enterprises in the European Union countries (EU-28) for the years 2018 and 2017. The following indicators of ICT usage were analyzed: fixed broadband access, the speed of the internet connections, the presence of the Internet (enterprises having a website), the use of social media, the use of cloud computing services, e-commerce indicators (the share of the enterprises making e-sales and the share of e-commerce in the total turnover) and the indicators of e-business integration - the share of the enterprises using enterprise resource planning (ERP), customer relationship management (CRM) and the supply chain management (SCM) software applications. A comparative analysis of the EU countries by the value of these indicators was carried out. The main focus in the analysis was to identify the factors that influence the difference in the value of the ICT indicators between the countries. The analysis has shown that the regional position, the geographic characteristics, the size of the country and the level of its economic development are the factors that influence these differences.U radu se analizira primena informaciono-komunikacionih tehnologija (IKT) u preduzećima u zemljama članicama Evropske unije (EU). Ciljevi analize bili su da se ispita dostignuti nivo u primeni IKT u preduzećima i da se istraže razlike u korišćenju IKT koje postoje među zemljama članicama EU. U analizi su korišćeni podaci EUROSTAT-a o primeni IKT u preduzećima Evropske unije (EU-28) za 2017. i 2018. Analizirani su sledeći indikatori primene IKT u preduzećima: širokopojasna internet konekcija, brzina internet konekcije, prisustvo na internetu (posedovanje Web sajta), korišćenje društvenih medija, korišćenje cloud računarstva, indikatori e-trgovine (udeo preduzeća koja prodaju svoje proizvode preko interneta i učešće e-trgovine u ukupnom prometu), i indikatori integrisanosti e-poslovanja (udeo preduzeća koja koriste integralni poslovni software, software za upravljanje odnosima sa klijentima i softver za upravljanje lancem snabdevanja). Izvršena je komparativna analiza zemalja EU po vrednosti ovih indikatora, sa ciljem da se utvrdi koji faktori utiču na razlike u vrednosti indikatora među zemljama. Analiza je pokazala da su regionalni položaj, geografske karakteristike, veličina zemlje i dostignut nivo ekonomskog razvoja faktori koji utiču na ove razlike

Primena vodećih indikatora u analizi i predviđanju ekonomske aktivnosti Srbije

The paper presents the search for the possibilities of using the leading indicators in analyzing and forecasting the economic activity in Serbia. The leading indicators for Serbia have not been identified so far. This is why the research of possibilities of their use required considering some important theoretical and methodological issues related to the cyclical analysis of the economic activity in Serbia and identification of the cyclical indicators. These issues are as follows: the general approach to cyclical analysis, the choice of a reference series and the choice of the appropriate methodology for identification of leading indicators. As an appropriate general approach to cyclical analysis the growth cycles approach has been considered. As the reference series the monthly GDP is used. The monthly GDP has been interpolated starting with officially available quarterly data and using Boot, Feibes and Lisman (BFL) method of temporal disaggregation. The trend has been estimated using HP filter. Starting from the general approach to cyclical analysis, the methodology of OECD has been proposed as the appropriate for identification of leading indicators for Serbia. The methodology of OECD is presented and the possibilities of using that methodology for Serbia have been considered. Finally, the possibilities of using the leading indicators in Serbia have been researched.Rad istražuje mogućnosti primene vodećih indikatora u analizi i predviđanju ekonomske aktivnosti Srbije. Vodeći indikatori za Srbiju još uvek nisu identifikovani, tako da je ispitivanje mogućnosti primene vodećih indikatora zahtevalo razmatranje određenih teorijskih i metodoloških pitanja koja su u vezi sa cikličnom analizom ekonomske aktivnosti Srbije i identifikacijom vodećih indikatora. Ova pitanja bila su: razmatranje opšteg pristupa cikličnoj analizi, izbor referentne serije, izbor odgovarajuće metodologije za identifikaciju vodećih indikatora. Kao odgovarajući opšti pristup cikličnoj analizi ekonomske aktivnosti, određen je pristup ciklusa rasta. Kao referentna serija u radu je korišćen mesečni bruto domaći proizvod, koji je dobijen vremenskom dezagregacijom zvanično raspoloživih kvartalnih podataka za bruto domaći proizvod na osnovu BFL metoda (Boot-Feibes-Lisman) vremenske dezagregacije vremenskih serija, pri čemu je za identifikaciju trenda korišćen HP (Hodrick-Prescott) filter. Polazeći od opšteg pristupa cikličnoj analizi, kao odgovarajuća metodologija za identifikaciju vodećih indikatora za Srbiju, predložena je metodologija OECD-a. Predstavljena je metodologija OECD-a i razmotrene su mogućnosti primene ove metodologije za Srbiju. Na kraju, istražene su mogućnosti primene vodećih indikatora za Srbiju

Statistički pokazatelji korupcije u javnom sektoru u Srbiji

The paper presents statistical indicators of corruption in public sector: The World Bank's aggregate indicator Control of Corruption and The Corruption Perception Index calculated by Transparency International. The values of those indicators for Serbia are given year by year, and the methodology of their construction is presented in brief. The other sources of statistical data about corruption in Serbia are also presented: the data which compile The Statistical office of the Republic of Serbia, those of The Public Prosecution of the Republic of Serbia, internal sources of data of domestic institutions, and public opinion surveys. It was pointed out that it is very difficult to assess the real level of corruption in Serbia, especially in public sector, on the basis of available data from those sources. The progress in the fight against corruption in Serbia is evaluated by The Council of Europe and The European Commission as slow on the basis of those data, the values of The Corruption Perception Index and on the basis of some additional information's. Perhaps the results of those evaluations would have been different if the data had been complete, updated, and if some domestic indicators of corruption or methods of evaluation had been constructed.U radu su predstavljeni statistički pokazatelji korupcije u javnom sektoru: agregatni indikator Kontrola korupcije Svetske banke i Indeks percepcije korupcije koji izračunava Transparency International. Vrednosti ovih indikatora za Srbiju su date po godinama i ukratko je predstavljena metodologija njihove konstrukcije. Predstavljeni su i drugi izvori statističkih podataka o korupciji u Srbiji: podaci Republičkog zavoda za statistiku Srbije, podaci Republičkog javnog tužilaštva, interni izvori podataka domaćih institucija i istraživanja javnog mnjenja o korupciji. Ukazano je na činjenicu da je na osnovu raspoloživih podataka iz ovih izvora teško utvrditi stvarni nivo korupcije u Srbiji, naročito u javnom sektoru. Na bazi podataka iz nabrojanih izvora, vrednosti Indeksa percepcije korupcije i na osnovu dodatnih informacija, napredak u borbi protiv korupcije u Srbiji je ocenjen kao spor od strane Saveta Evrope i Evropske komisije. Možda bi rezultati evaluacije napretka bili drugačiji da su podaci bili potpuniji, da su ažurirani i da postoje domaći indikatori korupcije ili metode evaluacije progresa u borbi protiv korupcije

Investigations of time and economic dimensions of the complex product production cycle

Obeležja savremene proizvodnje sa vrhunskom organizacijom i metodama upravljanja zasnivaju se na načelima ekonomije vremena i principima nove proizvodne filozofije-lean production. Proizvodnju treba organizovati po principu usisavanja, sa minimalnim zalihama, radeći samo ono što je stvarno potrebno, ni prerano ni prekasno. U radu je prikazan postupak projektovanja i rezultati istraživanja proizvodnog ciklusa složenog proizvoda koji se nalazi u proizvodnom programu kompanije 'Sloboda' Čačak.The features of contemporary production process of top organization and management methods are grounded on the principles of economies of times and the principles of lean production, a new philosophy of production. Production should be organized according to the push-pull principle, with minimum inventories, manufacturing only what is really necessary, neither too early, nor too late. The paper presents the design procedure and results of investigations on the production cycle of a complex product included in the production program of 'Sloboda' - Čačak Co