BEHAVIORAL ANALYSIS OF ECONOMIC CHOICE: CONTRIBUTION TO IMPROVING ECONOMIC RATIONALITY

If we start from the presumption that the aim of the theoretical analysis of the complex socio-economic reality is to provide certain knowledge by applying of which there can be improvement and betterment of that reality, then economical and theoretical mainstream usually does this starting from axiom of the rationality. On the other hand, if we keep in mind the current empirical data on the numerous problems and inefficient functioning of the economic actors, then the logical question that occurs is whether the presumption of the unlimited rationality of the economic subjects should be so easily idealised. Starting from the fact that the bihevioral economics has a special role in the powerful critical attack on the “strong core” of the neo-classical mainstream, this paper discusses numerous psychological limitations of the process of economic decision-making, and the possibilities of their overcoming. In relation to this, we especially emphasize the importance of the behavioral analysis and its instrumentalist support directed toward the improvement of economic rationality and the quality of human decisions. Key words: rational choice, behavioral economics, behavioral anomalies and biases, ‘new’ paternalis

Heat wave characteristics: evaluation of regional climate model performances for Germany

Heat waves are among the most severe climate extreme events. In this study, we address the impact of increased model resolution and tailored model settings on the reproduction of these events by evaluating different regional climate model outputs for Germany and its near surroundings between 1980–2009. Outputs of an ensemble of six EURO-CORDEX models with 12.5 km grid resolution and outputs from a high-resolution (5 km) WRF (Weather Research and Forecasting) model run are employed. The latter was especially tailored for the study region regarding the physics configuration. We analyze the reproduction of the maximum temperature, number of heat wave days, heat wave characteristics (frequency, duration and intensity), the 2003 major event, and trends in the annual number of heat waves. E-OBS is used as the reference, and we utilize the Taylor diagram, the Mann–Kendall trend test and the spatial efficiency metric, while the cumulative heat index is used as a measure of intensity. Averaged over the domain, heat waves occurred about 31 times in the study period, with an average duration of 4 d and an average heat excess of 10 ∘C. The maximum temperature was only reproduced satisfactorily by some models. Despite using the same forcing, the models exhibited a large spread in heat wave reproduction. The domain mean conditions for heat wave frequency and duration were captured reasonably well, but the intensity was reproduced weakly. The spread was particularly pronounced for the 2003 event, indicating how difficult it was for the models to reproduce single major events. All models underestimated the spatial extent of the observed increasing trends. WRF generally did not perform significantly better than the other models. We conclude that increasing the model resolution does not add significant value to heat wave simulation if the base resolution is already relatively high. Tailored model settings seem to play a minor role. The sometimes pronounced differences in performance, however, highlight that the choice of model can be crucial

Droughts in Germany: performance of regional climate models in reproducing observed characteristics

Droughts are among the most relevant natural disasters related to climate change. We evaluated different regional climate model outputs and their ability to reproduce observed drought indices in Germany and its near surroundings between 1980–2009. Both outputs of an ensemble of six EURO-CORDEX models of 12.5 km grid resolution and outputs from a high-resolution (5 km) Weather Research and Forecasting (WRF) run were employed. The latter model was especially tailored for the study region regarding the physics configuration. We investigated drought-related variables and derived the 3-month standardized precipitation evapotranspiration index (SPEI-3) to account for meteorological droughts. Based on that, we analyzed correlations, the 2003 event, trends and drought characteristics (frequency, duration and severity) and compared the results to E-OBS. Methods used include Taylor diagrams, the Mann–Kendall trend test and the spatial efficiency (SPAEF) metric to account for spatial agreement of patterns. Averaged over the domain, meteorological droughts were found to occur approximately 16 times in the study period with an average duration of 3.1 months and average severity of 1.47 SPEI units. WRF's resolution and setup were shown to be less important for the reproduction of the single drought event and overall drought characteristics. Depending on the specific goals of drought analyses, computation resources could therefore be saved, since a coarser resolution can provide similar results. Benefits of WRF were found in the correlation analysis. The greatest benefits were identified in the trend analysis: only WRF was able to reproduce the observed negative SPEI trends to a fairly high spatial accuracy, while the other regional climate models (RCMs) completely failed in this regard. This was mainly due to the WRF model settings, highlighting the importance of appropriate model configuration tailored to the target region. Our findings are especially relevant in the context of climate change studies, where the appropriate reproduction of trends is of high importance.</p

Cut Length Distributions of Haylage Particles

Alfalfa is one of the most important crops for forage production. Traditional method of alfalfa conservation assumes hay preparation. However, nowadays it is also commonly processed in the form of silage and haylage. Physiological effects of forages that are included in diets depend on plant species, stage of maturity, method of preservation and diet composition. Physical characteristics of rations for ruminants are primarily influenced by dietary forage to concentrate ratio, type of forages and concentrates, and mean particle size of feeds. Length distribution of forage particles represents an important parameter for ruminant’s diet formulation, especially for dairy cattle. During silage production, harvest considerations should be focused to obtaining the adequate particle size distribution of the ensiling crop particles. This paper presents results of testing three contemporary types of self-propelled silage harvesters applied in the alfalfa haylage preparation: Claas Jaguar 950, Krone Big X 700 and Krone Big X 500. All machines were adapted with pick-up headers. In the study are analyzed length distributions of chopped alfalfa particles. Resulting frequency distributions of produced haylage are characterised by high mass percentage of the fraction comprehending the largest particles. It is also evident that harvester Class Jaguar 950 achieved the mean chopping length closest to preset value

Hidraulički simboli - deo i: opšti simboli i oznake mernih instrumenata i indikatora

Hydraulic power transfer and management systems are widely used in modern agriculture, especially in agricultural engineering and the associated processing industry. They can be very simple, but also extremely complex, when precise matching of the interaction of their components in real time is very difficult to controll and achieve. In addition, the designs of a number of hydraulic components is sufficiently complicated for detailed representation on the corresponding hydraulic installation. In all cases, analyzing the performance characteristics of components and the entire hydraulic system, as well as understanding the structure of the hydraulic system, is of great importance. One of the generally accepted ways to facilitate and speed up these processes is the application of schematic diagrams of hydraulic systems and their subcircuits. Officially, hydraulic symbols are defined by ISO industry standards. Therefore, ideally, all hydraulic schemes should be configured using universal graphic symbols. Unfortunately, this is not always the case in technical practice. Depending on the manufacturer and/or dealer of the hydraulic equipment, the symbols of the associated schemes vary in a smaller or a greater extent. The real reasons for the existence of these differences can only be assumed. According to some authors, companies want their drawings to differ from the hydraulic schema of competitors. Therefore, the most commonly used hydraulic symbols are presented in this paper.Hidraulički sistemi prenosa snage i upravljanja široko su zastupljeni u savremenoj poljoprivredi, a posebno u poljoprivrednoj tehnici i pratećoj prerađivačkoj industriji. Mogu biti veoma jednostavni, ali i izuzetno složeni, kada je precizno usklađivanje međusobnih interakcija njihovih komponenata u realnom vremenu veoma otežano. Pored toga, konstrukcija velikog broja hidrauličkih komponenata je dovoljno komplikovana za detaljno predstavljanje u sklopu pripadajuće hidrauličke instalacije. U svim slučajevima, analizanje radnih karakteristika komponenata i celokupnog hidra-uličkog sistema, kao i razumevanje strukture hidrauličkog sistema, od neprocenjivog je značaja. Jedan od opšte prihvaćenih načina za olakšavanje i ubrzavanje ovih procesa je izrada i korišćenje šematskih dijagrama hidrauličkih sistema, kao i strujnih kola (podsistema) od kojih su sastavljeni. Zvanično, simboli hidraulike definisani su ISO industrijskim standardima. Stoga, u idealnom slučaju, sve hidrauličke šeme bi trebale sadržati univerzalne simboličke oznake. To ipak nije uvek slučaj u tehničkoj praksi. U zavisnosti od proizvođača i/ili prodavca hidrauličke opreme, simboli pripadajućih šema se nekada mogu razlikovati u izvesnoj meri. Stvarne razloge postojanja ovih razlika je moguće samo pretpostaviti. Prema nekim autorima, proizvođači i/ili prodavci žele da se njihovi crteži razlikuju od hidrauličkih šema konkurenata. Prema drugima, simboli su dizajnirani da predstave većinu raspoloživih komponenata, ali ipak ne mogu pokriti sve postojeće te se zato formiraju dodatni nestandardni simboli u nekim posebnim situacijama

Hidrostatički sistemi prenosa snage poljoprivrednih mašina: zapreminske pumpe

The paper presents and analyzes the hydrostatic transmission of power and motion. The most important elements of this group of systems and the possibilities of their application in agricultural technology are given. Particular attention is paid to the positive-displacement pumps that have the widest application in agricultural machinery: gear pumps with external and internal gears, vane pumps, piston-axial pumps with inclined swash plate and piston-axial pumps with inclined cylinder block. Two hydrostatic power transmission and control systems are also presented. The first is a very simple mechanical- hydraulic system of automatic leveling of self-propelled berry fruits harvester. In contrast, the other hydrostatic system is very sophisticated. It is implemented as a very complex combination of hydrostatic and mechanical power transmission subsystems, with the accompanying control digital electronic system, and is intended for the wheat harvester propulsion and steering.U radu je prikazan i analiziran hidrostatički prenos snage i upravljanja. Navedeni su najvažniji elementi ove grupe sistema i mogućnosti njihove primene u poljoprivrednoj tehnici. Posebno pažnja je posvećena zapreminskim pumpama koje nalaze najširu primenu u poljoprivrednoj mehanizaciji: zupčastim pumpama sa spoljašnjim i unutrašnjim ozubljenjem, krilnim pumpama, klipno-aksijalnim pumpama sa nagnutom kliznom pločom i klipno-aksijalnim pumpama sa nagnutim cilindarskim blokom. Prikazana su dva hidrostatička sistema prenosa snage i upravljanja. Prvi predstavlja veoma jednostavan mehaničko-hidraulički sistem automatske nivelacije samohodnog berača jagodastog voća. Drugi predstavljeni hidrostatički sistem spada u najsavremenije sisteme koji se koriste u poljoprivrednoj mehanizaciji. Izveden je kao veoma složena kombinacija hidrostatičkog i mehaničkog prenosnika snage sa pratećim upravljačkim digitalnim elektronskim sistemom, a namenjen je pogonu žitnog kombajna

Hidraulički simboli - Deo II: pumpe i izvršni organi

At the current level of technological development, it is widely accepted that survival and progress of modern agricultural technology (among other things) is based on the widespread application of electronically controlled hydraulic systems, supported by mechanical elements of power transmission and control. This paper is a logical continuation of the first part, entitled "Hydraulic symbols - part I: general symbols and designations of measuring instruments and indicators". Therefore, the current second part of the paper is devoted to the presentation and description of hydraulic symbols of pumps and various types of actuators: linear, rotary and oscillatory. Symbols of the combined-function devices, which can optionally function in two different operating modes, such as pumps or motors, are also shown. Standard symbols of all groups of hydraulic components, which are in the focus of this paper, are standardized and defined by ISO industry standards.Na sadašnjem nivou tehnološkog razvoja, opšte je prihvaćeno mišljenje da savremena poljoprivredna tehnika, između ostalog, svoj napredak zasniva na širokoj primeni elektronski kontrolisanih hidrauličkih sistema, podržanih mehaničkim elementima prenosa snage i upravljanja. Ovaj rukopis predstavlja logičan nastavak prvog dela rada, pod nazivom „Hidraulički simboli - deo I: opšti simboli i oznake mernih instrumenata i indikatora“, posvećenog pripadajućoj tematici. Zato je drugi deo rada posvećen prikazu i opisu hidrauličkih simbola pumpi i različitih tipova izvršnih hidrauličkih organa i to: linearnih, rotacionih i oscilatornih. Takođe su predstavljeni i simboli uređaja kombinovane namene, koji opciono mogu funkcionisati u dva različita radna režima, kao hidrauličke pumpe ili hidraulički motori. Simboli svih grupa hidrauličkih komponenata, koje su u fokusu ovog rada, standardizovani su i definisani ISO industrijskim standardima

Ventili kao upravljačke komponente hidrostatičkih sistema

Modern agricultural engineering involves the wide application of hydraulic and pneumatic systems for the transmission of power (energy) and control signals. This paper presents the most commonly used types of valves in hydraulic systems. In the literature, more classification of hydraulic valves is reported, according to their construction, purposes, etc., which, even within the same classification criteria, sometimes stronglu differ one from the another. Therefore, this presentation is organized by principled valve assignment into four basic groups based on purpose, although there are other divisions according to the purpose of the valve. Other classifications, although present in the available literature, have not been commented in detail, due to space constraints. In this manuscript, the basic elements of the construction of the most important types of valves are described and analyzed, their most important characteristics are described, the base functional principles and technical limitations described, and the given guidelines and recommendations for their optimal application.Efikasnu, ekonomičnu i samoodrživu savremenu poljoprivrednu tehniku teško je, pored niza drugih agroekoloških, tehničkih ekonomski i drugih zahteva, zamisliti bez širokog uključivanja manuelnih, mehaničkih, hidrauličkih, pneumatskih, električnih, analognih i digitalnih sistema upravljnja, kao i njihovih usklađenih međusobnih aktivnosti vezanih za prenos snage (energije) i upravljačkih signala. U ovom radu su prikazani najčešće korišćeni tipovi ventila u hidrauličkim sistemima. Literatura prikazuje više klasifikacija ventila, prema konstukciji, nameni itd., pri čemu se čak i isti tip ventila nekada svrstava u različite grupe. Zato su nekada i ventili svrstani u okviru istog klasifikacionog kriterijuma, mogu međusobno značajno razlikovati. Iz navedenih razloga, ovaj prikaz je organizovan principijelnim svrstavanjem ventila u četiri osnovne grupe, prema osnovnim namenama, mada postoje i drugačije podele prema nameni ventila. Ostale klasifikacije, prisutne u dostupnoj literaturi, samo su preliminarno komentarisane. U ovom radu su opisani i analizirani osnovni elementi konstrukcije najvažnijih tipova ventila, navedene njihove najbitnije tehničko-operativne karakteristike, opisani bazni funkcionalni principi i tehnička ograničenja, te date smernice i preporuke za njihovu optimalnu primenu u poljoprivrednoj tehnici

Hidraulički simboli - deo IV: razvodni ventili

The mechanization of a wide variety of production processes and operations in modern primary agricultural production, transport, storage and the accompanying food processing industry can hardly be accomplished without automation. In most cases, production efficiency and environmental sustainability require, among other things, accurate control of the flow of energy within the installations, work machines, devices and mechanisms used. From the point of view of the theory of automatic control and regulation, the elements of the engaged technique: machines, devices and mechanisms represent the objects of control. The controlled routing and optimal delivery of energy to desired management facilities is, as a rule, very rarely uniform, as it must have correctlyaligned timing with the current variable requirements of the production or operation process, which often change quite unpredictably over the time. The required amount of energy can be transferred to consumers in agriculture through the application of appropriate mechanical, electrical, pneumatic or hydraulic systems, as well as with their combinations. All existing kinds of energy transmission systems have certain advantages and disadvantages, with a common requirement for appropriate controls. In the focus of interest of this paper are the graphic symbols of the directional control valves for hydraulic transmission and control, designated as hydraulic directional control valves, or shorter, the hydraulic distributors.Mehanizacija mnogobrojnih proizvodnih procesa i operacija u savremenoj primarnoj poljoprivrednoj proizvodnji, transportu, skladištenju i pratećoj prehrambenoj prerađivačkoj industriji teško se može ostvariti bez automatizacije. U najvećem broju slučajeva, proizvodna efikasnost i ekološka održivost zahtevaju, između ostalog, preciznu kontrolu toka energije u okviru primenjenih instalacija, radnih mašina, uređaja i mehanizmima. Sa gledišta teorije automatskog upravljanja, elementi angažovane tehnike, mašine, uređaji i mehanizmi, mogu predstavljati objekte upravljanja. Kontrolisano usmeravanje i optimalno dostavljanje određene količine energije željenim objektima upravljanja po pravilu je veoma retko uniformno, jer mora biti usklađeno sa vremenski nepredvidivim promenama zahteva proizvodnog procesa ili operacije. Potrebna energija može se preneti prema potrošačima u poljoprivredi primenom odgovarajućih mehaničkih, električnih, pneumatskih ili hidrauličkih sistema, kao i njihovim sadejstvom. Svi postojeći tipovi sistema prenosa energije imaju izvesne prednosti i nedostatke, uz zajednicki zahtev za odgovarajućim upravljačkim elementima. U fokusu ovog rada su grafički simboli upravljačkih ventila hidrauličkog prenosa energije (snage) i upravljačkih signala, označeni kao hidraulički razvodni ventili, ili hidraulički razvodnici

Raspodela prašine u vazduhu staja za držanje krava

Among others, an airborne dust particles concentration is a crucial microclimate quality parameter of each livestock building. Increasing the concentration of dust particles affects the indoor air quality and health of employed workers and breeding animals. In order to enrich the exisiting data base and improve the understanding of mechanisms of controlling the microclimate conditions in livestock buildings, the influence of operational air flow rate of under-roof axial fans on airborne dust particles distribution crossover the tied cows barn has been analysed in present study. Six different air flow rates of both installed fans have been tested: 0 m3•h-1 (only natural ventilation), 23750 m3•h-1, 30750 m3•h-1, 37300 m3•h-1, 39900 m3•h-1 and 48000 m3•h-1. Measurements have been performed at four typical height levels (0,5 m; 1,0 m; 1,5 m and 2,0 m), cross-over the three lateral and four longitudinal characteristic building sections. Consequently, 48 measuring points were appropriately selected, in order to cover the whole indoor space in adequate way. Comparative analysis of air flow velocities and dust concentrations showed that this fan setup can provide satisfactory results under adequate operational regime. Certain working regimes were recommended for use, and the first fan rate step, generating the airflow of 23750 m3•h-1, or indoor air exchange level of approximately 16 1•h-1, has been found as the most suitable.Koncentracija prašine je važan mikroklimatski parametar u svakom stočar¬skom objektu. Njeno povećanje narušava kvalitet unutrašnjeg vazduha i zdravstve¬no sta¬nje zaposlenih radnika i smeštenih životinja. Pored ostalih uticaja, strujno polje va¬zdu¬ha u provetravanom prostoru predstavlja ključni parametar za kontrolu prisustva če¬stica prašine u vazduhu objekata za držanje domaćih životinja. U cilju proširivanja postojećih baza podataka i saznanja u oblasti istraživanja mikroklime u stočarskim objektima, u ovom radu je analiziran uticaj režima rada podkrovnih aksijalnih ventilatora na raspode¬lu čestica prašine u objektu za držanje krava u vezanom sistemu. Ispitano je šest različitih radnih režima ventilacije. Pri tome je ostvaren diskretan (diskontinualan) niz kontrolisanih protoka unutrašnjeg vazduha od 0 m3•h-1 (samo prirodna ventilacija), 23750 m3•h-1, 30750 m3•h-1, 37300 m3•h-1, 39900 m3•h-1 i 48000 m3•h-1 kroz radna kola svakog od dva instalirana ventilatora. To praktično znači da je celokupna zapremina unutrašnjeg vazduha eksperi¬mentalnog obje¬kta proticala približno 0; 16; 20; 25; 26,5; 32 puta u toku svakog sata kada je ventilacioni sistem bio aktivan. Merenja su izvedena na 4 karakte¬ristične visine (0,5 m; 1,0 m; 1,5 m i 2,0 m), u tri poprečna preseka i četiri podužna preseka objekta. Tako je dobijeno karakterističnih 48 mernih tačaka, čime je adekvatno pokriven ceo unutrašnji prostor staje. Komparativna analiza brzina strujanja vazduha i koncentracija prašine pokazala je da ova konfiguracija ventilatora može ostvariti zadovoljavajuće rezultate pri odgovarajućem režimu rada. Evidentirani su prihvatljivi ventilacioni režimi, a posebno je izdvojen treći ogledni režim, protoka vazduha 23750 m3•h-1 (približno 16 zapremina objekta na čas) je izdvojen kao najpovoljniji