Urban areas are formed aiming to satisfy multiple expectations of their citizens. Among the most significant expectations are resources availability, related to existential needs, efficiency in communication and satisfaction of other contemporary civilization and cultural needs. However, pursuance to create conditions for those needs satisfaction necessarily leads to high level of urban area construction. Thus, sort of paradox appears: aspiration to improvement of living conditions leads to negative effects which jeopardize the health and lives of urban population. This fact requires holistic approach, i.e. consideration of all aspects of life's needs of urban population in order to provide their long term sustainability. This paper aims to consider some aspects of urban areas sustainability relative to blue green cities philosophy.

The subject of the research in this paper is the artificial intelligence models through a modern methodological approach to solving complex water management problems. Fuzzy logic as new mathematics, neural networks and fuzzy expert systems open up great opportunities in simulating and solving real problems related to the division of water and water resources. When decision-makers seek optimum, in addition to technical and economic criteria, sometimes the decisive influence belongs to the low, ecology, political, territorial, social, religious or cultural criteria. The developed theoretical model was tested and confirmed by the development of an expert system for the selection of an optimal solution for the management and distribution of the water potential of the Drina River, in the zone of different entities, between the cities of Foča and Goražde. Holistic approach and synergy appreciation of all relevant criteria resulted in the fact that the solution found by the expert model was also implemented in practice, which is confirmation for the expert system developed.

The objective of this research work was to explore the scope, structure and quality of production and use of domestic wheat in the RS. The subject of the research was to determine the production of wheat in the Republic of Srpska, the needs for seed wheat, determine the amount imported, and to identify measures to increase domestic production of seed wheat and to reduce imports. The analysis of commercial wheat production in the period [2006][2007][2008][2009][2010] showed that the production took place in the average area of 44,017.6 ha, with an average yield of 3.28 t/ha and total production of 145,591 t. The highest level of wheat production was recorded in 2007 when it was 172,481 t, and a minimum production was in 2010 when it was 84,647 t. In the Republic of Srpska in 2010, the area under wheat amounted to 33,641 ha, which required about 8,410 tonnes of wheat seed, and only 4.27% of the quantities of seed wheat needed for the RS market were produced in the RS, the rest came from imports. According to the Indirect Taxation Administration data, the Republic of Srpska imported 125 t of wheat seed in 2009. The quantities of imported wheat vary considerably from year to year and are influenced by the weather in the sowing season and the prices on the market. Analysis of seed wheat in period 2006-2010 showed that the seed wheat occupied an average area of 128.8 ha, with the average yield of 4.06 t/ha and the total average production of 514.2 tonnes. The highest production was recorded in 2008 when it was 656.25 tonnes, and the lowest in 2010, 359.4 tonnes. Demand for wheat seed of the Republic of Srpska, based on five-year average, amounts to 13,205 tonnes, in which the domestic production share is 514 tonnes or 3.9%. The value of domestic wheat seed production in this period was BAM 393,616, and the value of missing quantities of seeds that are imported is BAM 9,824,152, based on the domestic price.

SAŽETAK:Monitoring stanja tribomehaničkih sistema ima veoma veliki značaj u razvoju teorije i prakse o trenju i habanju kao i teoriji podmazivanja. U savremenim tribomehaničkim sistemima se primenjuju različite fizičko hemijske i tribološke metode. Iskustva iz eksploatacije tehničkih sistema pokazuju da je predviđanje otkaza najefikasnije na osnovu praćenja parametara procesa habanja i čestica koje nastaju u ovom procesu. Sredstvo za podnazivanje kao treći elemenat u tribomehaničkom sistemu je nosilac informacija o stanju celog sistema sa aspekta triboloških i drugih procesa starenja.