Open space evaluation methodology and three dimensional evaluation model as a base for sustainable development trackingMelita Rozman Cafuta
, 2015, izvirni znanstveni članek
Opis: Sustainable development, as a concept of controlled development, is a management characteristic. Adaptation to progress is important to achieve sustainability. The research focus here is on developing an evaluation methodology for determining the characteristics of urban open space. A method was designed for use in the comparative analysis of environmental perception evaluation between different time sequences. It allows us to compare results before and after spatial interventions or spatial development tracking over time. The newly-developed SEC model (suitable for everyone, environmentally-accepted, and cost-effective) was an essential element used in the research methodology. The model was designed using the systematic principle, the top–down approach, and the decomposition method. Three basic dimensions were divided into six factors. Factors were divided into eighteen indicators that are either quantitatively or qualitatively assessed. Indicators were divided into several aspects. An instrument (questionnaire) was developed to support the evaluation methodology of urban open space characteristics. Every aspect belongs to a question in the questionnaire. The applicability of the SEC model was demonstrated in two case studies. Evaluation took place during two different time sequences, once during the day-time and once during the night. Obtained results provide useful information of the current spatial situation needed for sustainable development strategy preparation.
Ključne besede: urbano okolje, vizualna percepcija, vizualno zaznavanje, vidno zaznavanje, metodologija vrednotenja, SEC model
Objavljeno: 22.06.2017; Ogledov: 23; Prenosov: 0
Polno besedilo (2,65 MB)
On algebraic approach in quadratic systemsMatej Mencinger
, 2011, pregledni znanstveni članek
Opis: When considering friction or resistance, many physical processes are mathematically simulated by quadratic systems of ODEs or discrete quadratic dynamical systems. Probably the most important problem when such systems are applied in engineering is the stability of critical points and (non)chaotic dynamics. In this paper we consider homogeneous quadratic systems via the so-called Markus approach. We use the one-to-one correspondence between homogeneous quadratic dynamical systems and algebra which was originally introduced by Markus in (1960). We resume some connections between the dynamics of the quadratic systems and (algebraic) properties of the corresponding algebras. We consider some general connections and the influence of power-associativity in the corresponding quadratic system.
Ključne besede: quadratic systems, nonlinear systems
Objavljeno: 14.06.2017; Ogledov: 13; Prenosov: 1
Polno besedilo (2,74 MB)
An application of the Sakai's theorem to the characterization of H*-algebrasBorut Zalar
, 1995, izvirni znanstveni članek
Opis: The well-known Sakai's theorem, which states that every derivation acting on a von Neumann algebra is inner, is used to obtain a new elegant proof of the Saworotnow's characterization theorem for associative ▫$H^\ast$▫-algebras via two-sided ▫$H^\ast$▫-algebras. This proof completely avoids structure theory.
Ključne besede: mathematics, functional analysis, ▫$H^\ast$▫-algebra, involution, automorphism, derivation, centralizer, von Neumann algebra
Objavljeno: 14.06.2017; Ogledov: 11; Prenosov: 0
Polno besedilo (2,06 MB)
Traffic safety of older drivers in various types of road intersectionsTomaž Tollazzi
, Marko Renčelj
, Vlasta Rodošek
, Borut Zalar
, 2010, pregledni znanstveni članek
Opis: In industrialized countries people over 50 years of age represent a rapidly growing part of population. Their lifestyle is also becoming more active, which means that the percentage of older drivers in the population of all drivers is also increasing. Many different studies have shown that elderly drivers are more frequently involved in specific types of accidents, especially at intersections.
In the past 15 years there was a trend of increasing popularity of roundabouts in Slovenia. Their introduction was generally supported by the arguments of increased traffic-flow capacity and traffic safety as well. The studies on which these arguments are based were performed with an “ideal” type of driver in mind; the one that fully understands new rules and reacts correctly in all situations that may occur at such intersections, where there are no light signals to guide them. An elderly person does not necessarily conform to that ideal and if the percentage of elderly drivers became significant, the premises of the above mentioned studies may not be correct anymore which in turn implies that their results could also be questioned.
The present study concentrated on the evaluation of traffic safety of elderly drivers, at various types of intersection, from their own perspective. Various statistical analyses of obtained data were performed. The most important finding was that we may claim, with high degree of probability, that the average person of the age of over 60 feels more unsafe at double-lane roundabouts than they would feel had the same intersection been equipped with traffic lights.
Elderly traffic participants will always cause more accidents or participate in them due to hazardous factors. Challenge, arising from many different studies and researches, is in studying what measures and solutions can reduce the risk for elderly participants.
Ključne besede: traffic safety, road intersections, roundabouts, elderly people
Objavljeno: 06.06.2017; Ogledov: 33; Prenosov: 2
Polno besedilo (811,32 KB)
Theoretical model for determination of airspace capacityBranko Lučovnik
, Martin Lipičnik
, Domenik Lebar
, Janko Blatnik
, 2002, pregledni znanstveni članek
Opis: In the last decade, the constant air traffic growth has brought certain problems as well. While aircraft production and airline functioning are being stimulated by the competition, the situation in air traffic control and in infrastructure component is completely different. Air traffic management (ATM) is still owned by the state. The state, however, is known for the fact of not being a good manager and is solving problems slowly and not efficiently because of its large administration. There is a very strong trade union movement functioning in ATM system, which makes several rational decisions impossible. Critics of the current ATM system in Europe warn of increasing problems-delays and operational expenses. The control component is the only one among the four components of air traffic, which has not been liberalised and harmonised yet. There is no competition in the fields of air traffic. All matters are taken care of by CAA or by semi-private companies, owned by the state. According to air carriers which have to put in 4-9% of business expenses into terminal-and over-flights charges, these expenses are far too heavy a burden.
Ključne besede: air traffic, airspace capacity
Objavljeno: 06.06.2017; Ogledov: 34; Prenosov: 0
Polno besedilo (3,30 MB)
The impact of regulation 561/2006 on fleet management viewed through efficient use of drivers' working timeRobert Muha
, Drago Sever
, 2009, pregledni znanstveni članek
Opis: The introduction of contemporary procedures to fleet management processes has recently changed the work planning and supervision of driver's work activities. Tendencies to control the implementation of driver's work have been present in modem professional practice for quite a long time; however, the equipment available on the market limited its implementation. The intensified development of digital tachographs has, in technical terms, ensured such equipment considerably before the legislative groundwork was prepared for its practical implementation. The Commission Regulation (EC) No. 561/2006 (implementation of Social legislation relating to Road Transport) does not bring any essential novelties in terms of permitted workload. Consistent monitoring of drivers activities, made possible by digital tachographs, will have impact on the existing working methods. The topic of the present paper is in deep analysis of the impact of the mentioned regulation with special emphasis on the conditions for the regulation of the current stage of drivers work and on the expected consequences. The essential importance lies on the expected change in the mentality and approach to planning the driver's activities in the transport process on the part of the carrier: the outcome will eventually result in the efficiency of each individual carrier.
Ključne besede: fleet management, driver's work planning, digital tachographs
Objavljeno: 06.06.2017; Ogledov: 19; Prenosov: 0
Polno besedilo (2,98 MB)
The contribution to the procedure of capacity determination at unsignalized priority-controlled intersectionsTomaž Tollazzi
, 2004, pregledni znanstveni članek
Opis: The problem of minor vehicles crossing or merging into the major stream at unsignalized priority-controlled intersections is well-known. Numerous solutions involve various assumptions concerning the major headway distributions, number of major lanes, critical gap distributions, etc. Such cases can be divided into two main groups: intersections with two streams (one major and one minor stream) and intersections with more than two streams (more than one major stream and one minor stream). At roundabouts, also at single-lane roundabouts, there are similar problems like the ones at other unsignalized priority-controlled intersections. A vehicle at the roundabout approach can only cross the pedestrian crossing when a sufficient time-gap between two pedestrians (or cyclists) is provided. A vehicle at the roundabout entries can only merge into the major stream when a sufficient gap between the two vehicles in the major stream is provided. Because of that, single-lane round-abouts can also be treated as unsignalized intersections with two major lanes: the first one in its circulatory roadway and the second one on the pedestrian crossing.
Ključne besede: unsignalized intersection, roundabouts, capacity, two major streams, pedestrians, critical gap
Objavljeno: 06.06.2017; Ogledov: 19; Prenosov: 1
Polno besedilo (2,55 MB)
Slewing port jib cranesBoris Visočnik
, Stojan Kravanja
, 2002, pregledni znanstveni članek
Opis: The paper presents slewing port cranes with a luffing jib. The advantages of slewing port jib cranes are high lifting capacities, high speeds of re-loading and excellent mobility since they are capable of load lifting, travelling, luffing and slewing. The paper gives a detailed description of their characteristics such as the highest reached load-carrying capacities, speeds of motion and accelerations. It also presents the crane assembly, driving mechanisms, loads and load cases, transport by ships and testing of lifting capacity. As a practical example, the paper presents the slewing port jib crane with the capacity of 25/15/5 t at a 27/37/40 m radius made by the Slovenian companyMetalna Maribor for the shipyard 3. Maj, Rijeka, Croatia.
Ključne besede: cranes, port, port cranes, slewing port jib cranes
Objavljeno: 06.06.2017; Ogledov: 22; Prenosov: 1
Polno besedilo (3,08 MB)
Roundabout arm capacity determined by microsimulation and discrete functions techniqueTomaž Tollazzi
, Matjaž Šraml
, Tone Lerher
, 2008, izvirni znanstveni članek
Opis: The paper demonstrates the influence of the multi-channel pedestrian flow on the actual capacity of a one-lane roundabout, using micro-simulation and discrete functions. The proposed model is based on the theory of the expected time gap between the units of pedestrian traffic flow, which have the priority when crossing the arm of the roundabout. The proposed model represents an upgrade of the previous research in the field of modelling traffic flows in the one-lane roundabout.Apart from the multi-channel pedestrian flow the disturbances caused by the circular traffic flow of motorised vehicles at the roundabout are also considered. In this way the model can better illustrate the real conditions in traffic. A simulation analysis has been performed on the roundabout arm at Koroška Street in Maribor. The results of the analysis have indicated a relatively high reserve of the actual throughput capacity for the main motorized traffic flow in the analysed roundabout arm. The presented model represents a practicable and adaptable tool for planning the roundabout capacity in practice and for the sensitivity analysis of individual variables on the throughput capacity of the roundabout.
Ključne besede: roundabouts, traffic flow analysis, micro-simulation modelling, capacity analysis
Objavljeno: 05.06.2017; Ogledov: 32; Prenosov: 0
Polno besedilo (4,50 MB)
Reliability analysis of operation for cableways by FTA (fault tree analysis) methodSergej Težak
, Zdravko Toš
, Ivo Jurić
, 2010, izvirni znanstveni članek
Opis: This paper examines the reliability of the operation of cableway systems in Slovenia, which has major impact on the quality of service in the mountain tourism, mainly in wintertime. Different types of cableway installations in Slovenia were captured in a sample and fault tree analysis (FTA) was made on the basis of the obtained data. The paper presents the results of the analysis. With these results it is possible to determine the probability of faults of different types of cableways, which types of faults have the greatest impact on the termination of operation, which components of cableways fail most, what is the impact of age of cableways on the occurrence of the faults. Finally, an attempt was made to find if occurrence of faults on individual cableway installation has also impact on traffic on this cableway due to reduced quality of service.
Ključne besede: service quality, reliability, fault tree analysis, faults, quality, ski-tows, chairlifts, aerial ropeways, cableways
Objavljeno: 05.06.2017; Ogledov: 25; Prenosov: 0
Polno besedilo (653,93 KB)