MORFOLOŠKA VARIJABILNOST LISTOVA CRNE TOPOLE (Populus nigra L.) NA PODRUČJU VOJVODINE, SRBIJA

Morphological study of intra and interpopulation variability of black poplar leaves was carried on four natural populations located in the basin of the major rivers at the area of Vojvodina, Serbia. Research was conducted on the basis of nine leaf morphometric parameters, with descriptive and multivariate statistical analysis. Results show that within and between studied populations exists considerable variability, with the variability much more pronounced within than between populations. Given that the environmental conditions of investigated locations are uniform, it is assumed that the variability is consequences of the specific gene pool of these populations.Crna topola (Populus nigra L.) predstavlja jednu od bitnih pionirskih drvenastih vrsta (Pospiškova et al. 2004) koja je prilagođena specifičnim uvijetima poplavnog područja. Budući da unatrag nekoliko desetljeća čovek intenzivno kontroliše plavna područja, utvrđeno je da prirodna staništa autohtonih ritskih vrsta polako nestaju. Uzevši u obzir nestanak ovih ekosustava, prekomjernu eksploataciju autohtonih topola, introdukciju superiornih hibrida topola i mogućnost introgresija gena kultiviranih topola, crna topola se smatra ugroženom vrstom. Kako bi se mogle primijeniti odgovarajuće metode konzervacije, potrebno je utvrditi postojanje varijabilnosti unutar preostalih prirodnih populacija (Flush et al. 2002). Varijabilnost postojećih prirodnih populacija crne topole na području Vojvodine je u ovom istraživanju ispitana pomoću niza morfoloških svojstava lista.Istraživanja unutarpopulacijske i međupopulacijske morfološke varijabilnosti listova crne topole (Populus nigra L.) rađeno je na razini četiri prirodne populacije koje se nalaze u dolinama najvećih rijeka Vojvodine (Dunav, Tisa, Sava – Slika 1). Skupljanje uzoraka obavljeno je metodom slučajnog odabira u tijeku vegetacijskog perioda kada su listovi potpuno razvijeni. Prikupljeni su listovi srednjeg djela grančice dugorasta koje Tucović (1965) ističe kao najvažnije za karakteriziranje pojedinih sistematskih kategorija. Na herbariziranom materijalu analizirano je devet morfometrijskih svojstava (slika 2).Standardna deskriptivna statistika (prosječna vrijednost, min/max vrijednost, raspon varijacije, standardna devijacija, relativna standardna devijacija), analiza varijance (one way ANOVA), post hoc Tukey HSD test i klaster analiza (metoda najbližeg susjeda, Euklidska udaljenost) su provedeni kako bi se utvrdile razlike na unutarpopulacijskom i međupopulacijskoj razini.Rezultati analize varijance (tabela 2.) ukazuju na postojanje statistički značajnih razlika između individua u okviru populacija za sva ispitivana morfometrijska svojstva (p<0,000). Dok su rezultati analize varijance provedeni radi utvrđivanja značajnosti razlika između populacija pokazali da za svojstva b, d, f, h i i postoji statistički značajna razlika između populacija. Tukey testom i klaster analizom utvrđeno je da se populacija A najviše ističe, potom slijedi populacija C, dok su populacije B i D najsličnije. Rezultati analiza pokazuju izraženu varijabilnost kada su u pitanju parametri c, e, f i d za koje se smatra da su pod izrazitom genetskom kontrolom, dok parametri b, a i g koji se odlikuju velikom plastičnošću pokazuju manju varijabilnost, što ukazuje na slične stanišne uvjete istraživanih populacija.Dobijene statističke analize ukazale su da na unutarpopulacijskoj i međupopulacijskoj razini postoji značajna varijabilnost, pri čemu je varijabilnost unutar populacija dosta izraženija od varijabilnosti između populacija. Imajući u vidu da su stanišni uvijeti istraživanih populacija ujednačeni i na osnovi utvrđenih statističkih značajnosti može se zaključiti da su njihove razlike zanemarive, možemo zaključiti da je unutarpopulacijska različitost uzrokovana izrazitom heterogenošću analiziranih genotipova ovih populacija

New model of enterprises resource planning implementation planning process in manufacturing enterprises

This article presents new model of enterprises resource planning implementation planning process in manufacturing enterprises based on assessment of risk sources. This assessment was performed by applying analytic hierarchy process. Analytic hierarchy process method allows variation of relative importance of specific risk sources dependent on the section from which the risk source originates (organizational environment, technical issues, people issues, adoption process management, and external support). Survey was conducted on 85 manufacturing enterprises involved with an enterprises resource planning solution. Ranking of risk sources assessments returns most frequent risks of enterprises resource planning implementation success in manufacturing enterprises, and representative factors were isolated through factor analysis by risk source origin. Finally, results indicate that there are hidden causes of failed implementation, for example, risk source "top management training and education," from risk origin "adoption process management.

New model of enterprises resource planning implementation planning process in manufacturing enterprises

This article presents new model of enterprises resource planning implementation planning process in manufacturing enterprises based on assessment of risk sources. This assessment was performed by applying analytic hierarchy process. Analytic hierarchy process method allows variation of relative importance of specific risk sources dependent on the section from which the risk source originates (organizational environment, technical issues, people issues, adoption process management, and external support). Survey was conducted on 85 manufacturing enterprises involved with an enterprises resource planning solution. Ranking of risk sources assessments returns most frequent risks of enterprises resource planning implementation success in manufacturing enterprises, and representative factors were isolated through factor analysis by risk source origin. Finally, results indicate that there are hidden causes of failed implementation, for example, risk source "top management training and education," from risk origin "adoption process management.

Risk based maintenance strategy selection

This paper presents decision-making model for maintenance strategy selection. Problem of right maintenance strategy selection is one of the most important problem in manufacturing enterprises, process industries or enterprises where failure of equipment has major impact on production flow, people, environment or business costs. Presented decision making model for maintenance strategy selection takes into account risk exposure to mechanical equipment failure, business costs, people health and environmental safety. At the other hand each strategy options has its benefits expressed by cost savings. This decision making model for maintenance strategy selection try to optimize between these opposite influential criteria

Determining the Risk Level in Client Analysis by Applying Fuzzy Logic in Insurance Sector

The aim of the paper is to determine the risk level of a contract extension with the existing policyholders, which is further propagated to the business effectiveness and long-term sustainability of the company. The uncertainties in the relative importance of risk factors, their values, and risk levels are described by the linguistic forms, which are modeled by using the fuzzy sets theory. The evaluations of the relative importance of risk factors are stated as a fuzzy group decision-making problem. The weights of risk factors are obtained by using a fuzzy analytic hierarchy process. The determination of production rules for the assessment of the risk level is based on fuzzy IF-THAN rules. The verification of the model is performed by using real-life data originating from the insurance company which operates in the Republic of Serbia

Opportunities for the application of linear program­ming in forest management planning

In situations where it is necessary to consider a variety of options when making decisions in forestry (and in general), with the choice influenced by hardly comparable criteria and a number of conflicting interests, a possible solution is to use multiple criteria methods. One of these methods, which can be applied in forestry, is mathematical programming (in particular, linear programming). Linear programming has a long tradition of being used in the U.S. and European forestry, whereas in the forestry of Serbia it still represents a theoretically and practically unknown tool. Therefore, in this paper we analyze the possibility of applying the methods of linear programming in developing a plan of regeneration cutting in the poplar plantations of FMU "Topolik" managed by PE "Vojvodinašume." Using the aimed function (linear programming) and the corresponding software package the maximum yield that can be achieved by cutting the plantation was obtained. The planned management period was from 2012 to 2021 and its volume was 155 852 m3. The preset condition that the yield in half-periods remains equal was fulfilled (half-period I 77,925 m3, half-period II 77,927 m3). The maximum yield obtained with this methodology was by 4,040 m3 lower than the theoretically possible yield that would be obtained if all stands were cut down at the end of the second half-period, i.e. higher by 8,430 m3 than the yield that would be obtained if cutting of the stands were performed at the start of the management period. The results obtained and foreign experience in this area clearly indicate that linear programming can successfully be used to solve this problem and even more complex problems (than the one presented in this paper) in our local forest practice (multidimensional planning with a series of constraints). [Projekat Ministarstva nauke Republike Srbije, br. 37008: Održivo gazdovanje ukupnim potencijalima šuma u Republici Srbiji

Strategijski pristup upravljanja lancima snabdevanja sa stanovišta Lean distribucije

U radu se istražuje strategijski pristup upravljanja lancima snabdevanja sa stanovišta Lean distribucije. Upravljanje lancima snabdevanja je proces dizajniranja, planiranja, izvršenja, kontrole i nadgledanja aktivnosti lanaca snabdevanja sa svrhom da se kreira neto vrednost, koja izgrađuje konkurentnu infrastrukturu, balansira internacionalnu logistiku, sinhronizuje snabdevanje sa potrebama i meri performansu poslovanja na globalnom nivou. Najbolje kompanije na svetu nalaze novi izvor konkurentne prednosti u upravljanju lancima snabdevanja, koji sadrži veliki broj aktivnosti koje su integrisane, kako bi proizvod ili usluga za što kraće vreme došli na tržište i zadovoljili potrebe kupca. Istraživanje definiše pet osnovnih postavki implementacije strategije upravljanja lancima snabdevanja sa stanovišta Lean distribucije