bluuebunny/crossref_metadata_2025 huggingface dataset:
Vegetation height and cover fraction between 60° S and 60° N from ICESat GLAS data
Authors: Los S. O. , Rosette J. A. B. , Kljun N. , North P. R. J. , Chasmer L. , Suárez J. C. , Hopkinson C. , Hill R. A. , van Gorsel E. , Mahoney C. , Berni J. A. J.
Published: March 2012

Abstract. We present new coarse resolution (0.5° × 0.5°) vegetation height and vegetation-cover fraction data sets between 60° S and 60° N for use in climate models and ecological models. The data sets are derived from 2003–2009 measurements collected by the Geoscience Laser Altimeter System (GLAS) on the Ice, Cloud and land Elevation Satellite (ICESat), the only LiDAR instrument that provides close to global coverage. Initial vegetation height is calculated from GLAS data using a development of the model of Rosette et al. (2008) with with further calibration on desert sites. Filters are developed to identify and eliminate spurious observations in the GLAS data, e.g. data that are affected by clouds, atmosphere and terrain and as such result in erroneous estimates of vegetation height or vegetation cover. Filtered GLAS vegetation height estimates are aggregated in histograms from 0 to 70 m in 0.5 m intervals for each 0.5° × 0.5°. The GLAS vegetation height product is evaluated in four ways. Firstly, the Vegetation height data and data filters are evaluated using aircraft LiDAR measurements of the same for ten sites in the Americas, Europe, and Australia. Application of filters to the GLAS vegetation height estimates increases the correlation with aircraft data from r = 0.33 to r = 0.78, decreases the root-mean-square error by a factor 3 to about 6 m (RMSE) or 4.5 m (68% error distribution) and decreases the bias from 5.7 m to −1.3 m. Secondly, the global aggregated GLAS vegetation height product is tested for sensitivity towards the choice of data quality filters; areas with frequent cloud cover and areas with steep terrain are the most sensitive to the choice of thresholds for the filters. The changes in height estimates by applying different filters are, for the main part, smaller than the overall uncertainty of 4.5–6 m established from the site measurements. Thirdly, the GLAS global vegetation height product is compared with a global vegetation height product typically used in a climate model, a recent global tree height product, and a vegetation greenness product and is shown to produce realistic estimates of vegetation height. Finally, the GLAS bare soil cover fraction is compared globally with the MODIS bare soil fraction (r = 0.65) and with bare soil cover fraction estimates derived from AVHRR NDVI data (r = 0.67); the GLAS tree-cover fraction is compared with the MODIS tree-cover fraction (r = 0.79). The evaluation indicates that filters applied to the GLAS data are conservative and eliminate a large proportion of spurious data, while only in a minority of cases at the cost of removing reliable data as well. The new GLAS vegetation height product appears more realistic than previous data sets used in climate models and ecological models and hence should significantly improve simulations that involve the land surface.
Selecting the optimal method to calculate daily global reference potential evaporation from CFSR reanalysis data for application in a hydrological model study
Authors: Sperna Weiland F. C. , Tisseuil C. , Dürr H. H. , Vrac M. , van Beek L. P. H.
Published: March 2012

Abstract. Potential evaporation (PET) is one of the main inputs of hydrological models. Yet, there is limited consensus on which PET equation is most applicable in hydrological climate impact assessments. In this study six different methods to derive global scale reference PET daily time series from Climate Forecast System Reanalysis (CFSR) data are compared: Penman-Monteith, Priestley-Taylor and original and re-calibrated versions of the Hargreaves and Blaney-Criddle method. The calculated PET time series are (1) evaluated against global monthly Penman-Monteith PET time series calculated from CRU data and (2) tested on their usability for modeling of global discharge cycles. A major finding is that for part of the investigated basins the selection of a PET method may have only a minor influence on the resulting river flow. Within the hydrological model used in this study the bias related to the PET method tends to decrease while going from PET, AET and runoff to discharge calculations. However, the performance of individual PET methods appears to be spatially variable, which stresses the necessity to select the most accurate and spatially stable PET method. The lowest root mean squared differences and the least significant deviations (95% significance level) between monthly CFSR derived PET time series and CRU derived PET were obtained for a cell-specific re-calibrated Blaney-Criddle equation. However, results show that this re-calibrated form is likely to be unstable under changing climate conditions and less reliable for the calculation of daily time series. Although often recommended, the Penman-Monteith equation applied to the CFSR data did not outperform the other methods in a evaluation against PET derived with the Penman-Monteith equation from CRU data. In arid regions (e.g. Sahara, central Australia, US deserts), the equation resulted in relatively low PET values and, consequently, led to relatively high discharge values for dry basins (e.g. Orange, Murray and Zambezi). Furthermore, the Penman-Monteith equation has a high data demand and the equation is sensitive to input data inaccuracy. Therefore, we recommend the re-calibrated form of the Hargreaves equation which globally gave reference PET values comparable to CRU derived values for multiple climate conditions. The resulting gridded daily PET time series provide a new reference dataset that can be used for future hydrological impact assessments in further research, or more specifically, for the statistical downscaling of daily PET derived from raw GCM data. The dataset can be downloaded from http://opendap.deltares.nl/thredds/dodsC/opendap/deltares/FEWS-IPCC.
An algorithm to detect sea ice leads by using AMSR-E passive microwave imagery
Authors: Röhrs J. , Kaleschke L.
Published: March 2012

Abstract. Leads are major sites of energy fluxes and brine releases at the air-ocean interface of sea-ice covered oceans. This study presents an algorithm to detect leads wider than 3 km in the entire Arctic Ocean. The algorithm detects 50 % of the lead area that was visible in optical MODIS satellite images. Passive microwave imagery from the Advanced Microwave Scanning Radiometer – Earth Observation System (AMSR-E) is used, allowing daily observations due to the fact that AMSR-E does not depend on daylight or cloud conditions. Using the unique signatures of thin ice in the brightness temperature ratio between the 89 GHz and 19 GHz channels, the algorithm is able to detect thin ice areas in the ice cover and is optimized to detect leads. Leads are mapped for the period from 2002 to 2011 excluding the summer months, and validated qualitatively by using MODIS, Envisat ASAR, and CryoSat-2 data. Several frequently recurring large scale lead patterns are found, especially in regions where sea ice is known to drift out of the Arctic Ocean.
A Rediscovered Ancient History of Motivational Interviewing and its Measurement
Authors: Dunn Christopher W. , Lord Sarah Peregrine , Lowe Jessica , Joesch Jutta , Atkins David C.
Published: March 2012

We wrote this piece for coding teams around the world, hoping to raise some measurement issues, to inspire, and to entertain (perhaps not in that order). This one’s for you, coders and for you, trainers of coders, you who work so hard to measure Motivational Interviewing using the standardized coding systems such as the MISC, MITI, and SCOPE.
Spontaneous Breathing of Heliox Using a Semi-Closed Circuit: A Bench Study
Authors: Roubík Karel , Zazula Roman , Strnadová Adéla , Zábrodský Vladimír , Spálený Antonín , Müller Martin , Chlumský Jan , Tyll Tomáš
Published: March 2012

Introduction:

The use of helium-oxygen mixture (heliox) for ventilation has an advantage in patients with obstruction of the airways. The physical properties of helium enable an easier gas flow through the airways; this enables easier breathing for the patient when compared to standard ventilation of air. A high cost of heliox falls within the factors that limit the use of heliox in clinical practice. At present, heliox is administered by use of an open circuit. The aim of this study is to propose a way of heliox administration that reduces heliox consumption but does not affect the positive heliox effects upon the airway resistance.

Methods:

To minimize consumption of heliox, a semi-closed circuit has been designed. The circuit is a modification of an anesthetic circuit composed of parts with the lowest possible resistances. As any circuit has its own resistance, the evaluation of its possible negative effect upon the work of breathing of patients with exacerbation of chronic obstructive pulmonary disease (COPD) has been conducted.

Results:

A semi-closed circuit for heliox administration has been constructed and evaluated. The intrinsic resistance of both the inspiratory and expiratory limbs of the circuit is less than 140 Pa·s/l. This resistance does not represent a significant workload for a patient with COPD exacerbation whose airway resistance is 10 to 20 fold higher.

Conclusions:

The designed semi-closed circuit offers a potential benefit of heliox in patients with COPD exacerbation.
In Vitro Investigations of Citrate Clearance with Different Dialysis Filters
Authors: Hartmann Jens , Strobl Karin , Fichtinger Ute , Schildböck Claudia , Falkenhagen Dieter
Published: March 2012

Objective:

In extracorporeal blood purification, citrate anticoagulation offers several substantial advantages over conventional heparin anticoagulation. However, there is still a lack of information on citrate kinetics, especially on the citrate clearance of conventional hemodialyzers. The aim of this study was to investigate the citrate clearance for different hemodialysis filters as a basis for the development of an intelligent citrate-calcium infusion algorithm.

Materials and Methods:

For our experiments, the Fresenius 4008H dialysis machine and the dialysis filters FX 60, F6 HPS, F8 HPS (Fresenius Medical Care, Bad Homburg, Germany), Polyflux 140H and 14L (Gambro Holding, Stockholm, Sweden), Xenium 130 (Baxter AG, Vienna, Austria) and APS-650 (ASAHI Kasei Kuraray Medical, Chiyoda-ku, Japan) were used. Clearance calculations were performed based on plasma/blood flow rate and the citrate concentrations at filter inlet and outlet. All experiments were carried out in vitro with fresh frozen plasma (FFP) or whole blood.

Results:

The results prove that citrate clearance is significantly higher with high-flux filters than with low-flux filters. Higher dialysate flow rates cause a more effective removal of citrate. The citrate clearance for low-flux and high-flux filters was 71 ± 7 and 86 ± 1% of the urea clearance, respectively.

Conclusions:

Citrate can efficiently be removed with standard hemodialysis. However, depending on the infused amounts as well as on the patient - especially in patients with impaired liver function - the use of a high-flux dialysis filter and a high dialysate flow rate should be considered to minimize the risk of citrate accumulation.
Avoiding or Promoting Graphite in Carbon-Rich Chromium-Containing CoNiFe Cast Alloys—Part 1: Preliminary Thermodynamic Exploration
Authors: Berthod Patrice
Published: March 2012

The thermodynamic equilibria of alloys, based on Co, Ni, and Fe rich in chromium and carbon over a [500; 1500°C] range of temperature, were determined using thermodynamic calculations. The probable types of microstructures (hypo- to hypereutectic) as well as the phase present at high temperature (matrix network, types of carbides, presence or not of graphite) were predicted. From these results new chromium contents to either avoid or promote the presence of graphite were chosen and the as-cast microstructures of the corresponding real alloys were anticipated, before their elaboration and microstructure characterization in the second part of this work.
Angiogenesis in Non-Hodgkin's Lymphoma: An Intercategory Comparison of Microvessel Density
Authors: Aggarwal Deepti , Srivastava Gunjan , Gupta Ruchika , Pant Leela , Krishan Gopal , Singh Sompal
Published: March 2012

Background. This study was aimed at comparing angiogenesis, seen as microvessel density (MVD) in subtypes of non-Hodgkin’s lymphoma (NHL). Methods. In this study, 64 cases of NHL diagnosed over a three-year period were included along with 15 lymph node biopsies of reactive hyperplasia. NHLs were classified using REAL classification, and immunohistochemistry was performed for CD34 in all cases. CD34-stained sections were evaluated for “hot spots,” where MVD was assessed and expressed as per mm2. Appropriate statistical methods were applied. Results. There were 6 cases of well-differentiated lymphocytic lymphoma (SLL), 21 diffuse large B-cell lymphoma (DLBCL), 15 follicular lymphoma, 10 lymphoblastic lymphoma, 7 MALToma, and 5 peripheral T-cell lymphoma (PTCL). Mean MVD was highest in reactive hyperplasia (191.92±12.16 per mm2) compared to all NHLs. Among NHLs, PTCL demonstrated the highest MVD (183.42±8.24) followed by DLBCL (149.91±13.68). A significant difference was found in MVD between reactive and individual lymphoma groups. SLL had significantly lower MVD than other lymphoma subtypes. Conclusion. Angiogenesis, assessed by MVD, showed significant differences among subtypes of NHL, especially the indolent types like SLL. The higher MVD in aggressive lymphomas like PTCL and DLBCL can potentially be utilized in targeted therapy with antiangiogenic drugs.
No Name, No Game
Authors: Samyn Yves , De Clerck Olivier
Published: March 2012

(no abstract)
Solve It!: Trains of Thought
Authors: Bair Sherry , Mooney Edward S.
Published: March 2012

An open-ended activity for students. Teachers can send in their most interesting student work for inclusion in Solve It! Student Thinking.
Palette of Problems – April 2012
Authors: Rock David , Porter Mary K.
Published: March 2012

A monthly set of problems is aimed at a variety of ability levels.
Where Are the Congruent Halves?
Authors: Obara Samuel
Published: March 2012

Try this activity that requires creating two polygons from one to apply knowledge of congruency and transformations and develop spatial reasoning.
Evolution of Traditional Outsourcing into Innovative Intelligent Outsourcing - Smartsourcing
Authors: Bajec Patricija
Published: March 2012

The concept and practice of traditional outsourcing is certainly not a new concept. Globalisation, competition and other market pressures have driven more businesses to consider using logistics provider to increase efficiency and effectiveness [11].
Many companies have successfully used traditional outsourcing to lower costs and have improved the bottom line. However, unless the company’s efforts are unusually good, true competitive advantage is fleeting when competitors begin outsourcing and achieving similar results [2].
Some companies have discovered even greater returns are possible and are now using advanced form of outsourcing – intelligent outsourcing or smartsourcing, to drive new revenues, quicken time-to-market, and increase innovation [2]. This shift, from traditional outsourcing to intelligent outsourcing - smartsourcing which has become a competitive advantage and is likely over time to become a competitive necessity for all, will be analysed in this paper.
KEY WORDS: logistics, growth, globalization, traditional outsourcing, innovation, intelligent outsourcing - smartsourcing
Simulation Method for Evaluation of LNG Receiving Terminal Capacity
Authors: Dundović Čedomir , Basch Danko , Dobrota Đorđe
Published: March 2012

Owing to ever increasing share of the natural gas in the world consumption of the power sources, the international maritime traffic with the liquefied gas is recording constant growth with even greater future anticipations. It results in the need for the construction of new LNG receiving terminals. In order to be integrated in those trends and to make provisions for additional quantities of power sources necessary for its future economic development, the Republic of Croatia is making plans for the construction of such a terminal. Successful planning and designing of LNG terminal depends on the application of appropriate methodology for the evaluation of terminal capacity. This paper gives a simulation method for the evaluation of receiving LNG terminal capacity.
KEY WORDS: liquefied natural gas, receiving terminal, evaluation of terminal capacity, model, discrete simulation.
Possibilities of Logistics Policy Improvement
Authors: Průša Petr , Tilkeridis David
Published: March 2012

The paper presents the strategic logistics management with emphasis on clear, accurate and effective material flow from the suppliers and internally, as well as an outline of the logistics policy for continuous improvement. The implementation of a complete Supplier Logistics Performance System is essential to support internal processes efficiency and establish a continuous improvement system according to the main logistics policy. Every company should consider such a system in order to win in the challenging field of current industry.
KEY WORDS: logistics policy, logistics continuous improvement system, Electronic Data Interchange (EDI), Logistics Key Performance Indicators (LKPI)
Analysis of Traffic Accidents in the Area of Small Towns in the Republic of Croatia
Authors: Višnjić Vinko , Pušić Marko
Published: March 2012

The safety of road traffic in small towns in the Republic of Croatia is not at a satisfactory level. As proof, the safety of road traffic participants in the area of the town of Nova Gradiška and its wider environment has been studied and analyzed. The paper includes the available data in the period from 2000 to 2007. The analysis and the assessment of road traffic safety can be applied also to other towns and counties of the Republic of Croatia. Having in mind that there are 531 settlements in the Republic of Croatia (119 towns and 412 districts), out of which only 78 are larger than 10,000 inhabitants or 14.69% of the total number, which means that the analysis could be made for any settlement in the Republic of Croatia. The road traffic safety assessment was conceived according to the modified Smeed model which may be applied for any settlement or town. The road traffic safety analysis has led to the conclusion that safety of all the traffic participants is endangered. This paper provides solutions about what has to be done in order to reduce the danger to all the road traffic factors.
KEY WORDS: drivers, traffic, traffic accidents, safety and small towns
Comparison of Delays at Signal-controlled Intersection and Roundabout
Authors: Ištoka Otković Irena , Dadić Ivan
Published: March 2012

Delays belong to standard parameters used for the evaluation of any type of intersection and they are taken in the evaluation of the level of service of an intersection. Intersections with shorter delays bring about economical benefits both for the users and the community, and enable greater efficiency of a traffic system, which is becoming a significant criterion with the increasing motorization. The case studies carried out in Europe and worldwide reveal that roundabouts bring delay savings if compared with other intersections of the same operational level and nearly the same traffic volume. The paper shows the results of the comparison analysis of the roundabout and the signal-controlled intersection in the city of Osijek, Croatia. The statistical indicators have given the basis for the evaluation of delays at the observed intersections, offering at the same time the possibility to compare the analysis conclusions on the local level with the conclusions of the case studies carried out throughout Europe and worldwide.
KEYWORDS: delays, roundabout, signal-controlled intersection
Forecasting Methodology of Maritime Passenger Demand in a Tourist Destination
Authors: Krasić Davor , Gatti Petra
Published: March 2012

Maritime passenger demand forecasting is a task that is almost always present in the development studies of passenger ports, both due to operational and investment requirements. If a port belongs to a tourist destination, then there is a reasonable intention to use the forecasting model in order to establish the dependence between the passenger and tourist demand. Since the reliability of forecasting depends to a great extent on the quality and availability of data, the forecasting model is often a compromise between the theoretical assumptions and practical possibilities. This paper presents the approach to maritime passenger demand forecasting using a case study of the tourist destination – Poreč, which has been the strongest destination in Croatia regarding tourist traffic for many years. The presented forecasting models can serve as one of the guidelines for further study of the relations between traffic and tourism.
KEY WORDS: forecasting maritime passenger demand, forecasting tourist demand, traffic and tourism
Application of Standards in Auditing of Stations for Technical Inspection of Vehicles
Authors: Zovak Goran , Čala Ivo , Šiško Igor
Published: March 2012

The HRN EN ISO/IEC 17020:2005 requirements have been applied to the auditing of the operation of the stations for technical inspection of vehicles which, as part of the system of technical inspections and registration of vehicles in the Republic of Croatia is carried out by the Croatian Automobile Club, based on the public accreditation issued by the Ministry of the Interior of the Republic of Croatia. The direct consequence of the application of this standard, i. e. the implementation of the quality management system is the improvement of the quality and efficiency in performing the respective activity, thus raising the level of technical roadworthiness of vehicles, i. e. traffic safety on the roads in the Republic of Croatia.
KEY WORDS: supervisory/inspection bodies, quality, quality management, technical inspection of vehicles, auditing
Comparative Analysis of Cargo Flows on Branches VB and VC of the Pan-European Corridor V
Authors: Poletan Jugović Tanja , Jolić Natalija , Kavran Zvonko
Published: March 2012

Pan-European Corridor V that passes through the territory of the Republic of Croatia, i.e. Branches VB (Rijeka-Zagreb-Budapest) i VC (Budapest-Osijek-Sarajevo-Ploče) are of extreme importance for the traffic and economic system of the Republic of Croatia and the wider European area. Taking this into consideration, this study has analysed the relevant indicators of the traffic growth, structure and dynamics of the cargo flows on the Branches VB and VC of the Pan-European Corridor V. The cargo flows, as important elements of the traffic demand have been analysed regarding the presence of competition of alternative North-Adriatic and North-European traffic routes as important element of competitive environment in fighting to attract valuable transit market of Central Europe. Based on a detailed analysis of concrete statistical data, significant conclusions are derived about: quantity, dynamics and structure of the cargo flows, current traffic demand, competitiveness of corridors on Central European transit market, expected traffic demand, and conclusions about factors and circumstances that would positively, i.e. negatively affect the growth of cargo flows, and thus also the valorisation of the analysed Branches VB and VC of the Pan-European Corridor V within the European environment.
KEY WORDS: Pan-European Corridor V, branches VB and VC, cargo flows, intensity, structure, dynamics, traffic demand
Elaborating Cost and Performance Management Methods in Transport
Authors: Bokor Zoltán
Published: March 2012

Transport companies are facing management problems of enhancing operation efficiency at limited resources. The decision-making procedures applicable to solve such problems can be made more reliable if relevant information on basic components of business or technology processes are available. This information base can be produced by using cost and performance management methods combining financial and technology system parameters. The paper aims at summarising the research results conducted in the field of developing cost and performance controlling tools using this approach for the case of different transport companies. After explaining the main modelling principles, the experiences of empirical pilot projects are discussed. The preliminary results of these projects have proved the significance of the elaborated methodology. At the same time, it can also be concluded that the modelling tool shall be adapted to the specific circumstances of the examined transport companies before practical implementations.
KEY WORDS: cost calculation, performance management, controlling
Urban Commuting and Daytime Population in Small Areas of a Metropolis:A Case Study of Brno, Czech Republic
Authors: Akkerman Abraham , Kudrna Jan , Apeltauer Tomáš
Published: March 2012

A simplified modelling approach to urban commuting patterns is achieved by focusing on daytime populations rather than on commuters, or on the commuting process itself. Whereas past studies were usually economic in nature, and viewed commuting as a process within the continuum of urban space and time, the approach addressing daytime populations transforms the modelling attempt into a demographic deliberation of a binary situation where switching of values between daytime and night-time indicators in each subarea throughout a metropolis is considered. The present study shows that such a focus on diurnal change as a binary concept offers a new paradigm in conceptualizing metropolitan commuting and transportation. Under certain assumptions, rooted in recent observations of metropolitan areas elsewhere, this study conjectures an analytic function for the estimation of daytime populations in small areas throughout the metropolitan region of Brno, Czech Republic. The conjectured relationship is a logistic function that utilizes as its independent variable the average household size in each of the subareas throughout the metropolitan region. Based on the data from the Czech census of 2001, the distributions of average household size and of residential populations throughout the metropolitan region are applied in a case study illustrating the utility of the proposed approach for the estimation of daytime populations throughout the region. The iterative procedure advanced here offers considerable potential for further applications elsewhere.
KEY WORDS: metropolitan commuting, urban transportation, Brno, daytime population, average household size, logistic function, small area demography
Air Freight and Logistics Services
Authors: Kiso Fadila , Deljanin Abidin
Published: March 2012

Air transport industry has gradually increased its share of global passenger and freight traffic, and this trend has accelerated in the last 40 years. For the past decade, air-freight traffic growth has outpaced air passenger traffic growth by 1-2% each year. In the past, air-freight sector offered limited services, with heavy reliance on several intermediaries and a significant dependence on air passenger operations. The sector can now be characterized as a sophisticated, innovative one, relying heavily on new electronic technologies, offering a wide range of transport and logistical products through dedicated specialist freight operators. With increasing emphasis on the globalization of trade and economic activity, air-freight growth is expected to continue to outpace air passenger traffic growth. The air-freight growth is expected to be greatest in the Asian markets (intra-Asia; North America-Asia; Europe-Asia and Australasia). The process of physical distribution of freight has become a highly sophisticated operation, with increasingly greater reliance being placed on the use of new technology to assist in the movement, storage, and tracking of consignments. But transport is just one component in this logistics chain. In this paper, air-freight sector is examined in terms of its structure, organization, its role in the supply chains, the main trends in the recent period, constraints facing the sector and the future prospects in air-freight sector.
KEY WORDS: air freight organization, development, trends, forecast, logistics services
Development, Design and Flight Test Evaluation of Continuous Descent Approach Procedure in FIR Zagreb
Authors: Novak Doris , Bucak Tino , Radišić Tomislav
Published: March 2012

As part of Local Conversion and Implementation Plan which is based on the EUROCONTROL Revised Convention the Republic of Croatia has undertaken to make a plan of implementing the Basic Continuous Descent Approach procedures. This paper addresses the issue of navigational path optimization for the A-319/320 commercial aircraft within the fleet of Croatia Airlines, during the approach part of flight, which has a positive effect on fuel consumption, greenhouse gas emission and area of surface affected by noise. The experiments were carried out in real conditions, using internal sensors onboard (Flight Data Recorder) and independent GPS system. Two types of approach were tested: Continuous Descent Approach (CDA) and Step Down Approach. The implementation of CDA procedures, just for the fleet of Airbus 320/319 aircraft of the Croatia Airlines results in approximate calculation in fuel saving which amounts to 1.5 x 106 kg annually (only on Zagreb airport). In this way, the productiveness of an air carrier, which is an integral part of the traffic process along with the airports and air traffic control, is directly increased, thus fulfilling the purpose of air traffic technology research.
KEY WORDS: navigational procedures, continuous descent approach, air traffic, ecology
Impact of a Mediating Role of Repurchase Intentions on Customer Retention
Authors: Ambrož Milan , Lotrič Branko
Published: March 2012

Research in the area of packaged tour services, provided by the national and foreign tour operators has concentrated on mutual relationships among tourist-perceived service quality, satisfaction and repurchase intentions. However, little research in this domain has been done to explain the impact of repurchase intentions of experienced tourists on the relation between perceived quality of service and their satisfaction. This model was tested using substantial data set of experienced tourists with time span of three years. While previous literature has suggested that quality perceptions impose direct effect on tourist satisfaction, this study shows that such effect is more powerful when mediated by repurchase intentions of experienced tourists. The quality of packaged tour services mediated by repurchase intentions of the experienced tourist is expected to be paramount for the retention of the tourist in the long term.
KEY WORDS: repurchase intentions, quality, packaged service, services chain, tour operator, retention, tourist satisfaction.
Technical Documentation in Traffic Technology
Authors: Čurepić Danko , Toš Zdravko
Published: March 2012

The requirements for the prompt usage of traffic infrastructure capacities define the technological frames which ensure updated maintenance and development of new traffic infrastructure capacities by implementing graphical and computer systems. Technical documentation (TD) based on the technology of geographic information systems (GIS) allows fast analysis of graphical and alphanumerical data with the aim of identifying spatial relations among various cartographic elements. The paper analyses and presents the methodological bases of building GIS with the aim of designing the traffic network topology, as well as structural and functional analysis which uses the acquired knowledge to propose concrete solutions on connecting data about the position of infrastructure facilities with their properties in the railway traffic safety.
KEY WORDS: technical documentation, geographic information system, structural and functional analysis, software for technical drawing, signalling devices, railway
Possible Collision Avoidance with Off-line Route Selection
Authors: Krile Srećko , Peraković Dragan , Remenar Vladimir
Published: March 2012

The paper describes the traffic flow problems in telecommunication networks based on the Internet protocol. The main aim of telecommunication network operator today is to offer an SLA (Service Level Agreement) contract to end users, with provided QoS (Quality of Service) for different classes of services. In order to achieve this, it is necessary to establish the routes between marginal network nodes meeting the network traffic requirements and optimizing the network performances free of simultaneous flows conflicts. In DiffServ/MPLS (Multi-Protocol Label Switching) networks traffic flows traverse the network simultaneously and there may come to collision of concurrent flows. They are distributed among LSPs (Labeled Switching Paths) related to service classes. In LSP creation the IGP (Interior Gateway Protocol) uses simple on-line routing algorithms based on the shortest path methodology. In highly loaded networks this becomes an insufficient technique. In this suggested approach LSP need not necessarily be the shortest path solution. It can be pre-computed much earlier, possibly during the SLA negotiation process. In that sense an effective algorithm for collision control is developed. It may find a longer but lightly loaded path, taking care of the collision possibility. It could be a very good solution for collision avoidance and for better load-balancing purpose where links are running close to capacity. The algorithm can be significantly improved through heuristic approach. Heuristic options are compared in test-examples and their application for collision control is explained.
KEYWORDS: Telecommunication networks, collision avoidance, multi-constraint route selection, self-organizing systems, MPLS, QoS
Air Transport and Logistics in Pandemic Outbreak of Influenza A (H1N1) virus
Authors: Majić Zvonimir , Jukić Irena , Pavlin Stanislav
Published: March 2012

In April 2009, the WHO, (World Health Organization) evaluated the available data on the swine influenza A (H1N1), confirmed the outbreak and declared decision on raising the pandemic phase from five to six. IATA, (International Air Transport Association) invited the airlines to support WHO’s reference laboratories around the world in handling specimens should the outbreak expand further. The specimens shall be transported according to the regulations stipulated for acceptance and transportation of dangerous goods by air. The paper analyses the current infrastructural situation at the airports in Croatia, predispositions related to the trained staff and coordination procedures with the relevant institutions. The implementation of activities complying with the international regulations are suggested in order to conduct measures fighting the pandemic in Croatia.
KEY WORDS: pandemic outbreak, regulation, recommendation, specimen, responsibilities, transportation and logistic for biological substances
Influence of Sustainable Development Guidelines on Dangerous Goods Haulers
Authors: Muha Robert
Published: March 2012

In more advanced countries, the sustainable development concept was accepted both by the politicians and the industrial sector as the underlying philosophy for the preparation of development strategies, practically in all fields. This means using the natural resources within the limits of their renewability, and seeing that the resulting emissions have no negative impact on the environment. The development of Environmental Management Systems (EMS) commenced as a response to global environmental issues and as recognition of awareness that sustainable development is prerequisite for keeping the natural system in proper balance. Road transport of dangerous goods is a very complex activity representing a major potential danger to people and environment. For that very reason, the introduction of certain system tools (standardization of operations), that was a step forward to a safer and more effective operation of the carriers of dangerous goods by road was so welcome. However, this policy requires adequate business environment to be prepared, which is based on transparency and smooth operations as an important marketing advantage that has a bearing on every company’s economic performance.
KEY WORDS: sustainable development, road transport of dangerous goods, Environmental Management System (EMS), Responsible Care (RC), ISO 140001, Safety and Quality Assessment System (SQAS).
Model for Optimal Project Portfolio for the Construction of Railway Infrastructure on Corridors V and X
Authors: Hauc Anton , Bastič Majda , Jurše Lidia , Pšunder Mirko
Published: March 2012

The construction of railway infrastructure should be dealt with as a national strategic development programme, which — due to technical, geographical, logistical, and other requirements — is carried out through a number of projects and represents a complex multiple project operation for investors, contractors, and other influential players. The national strategic development programme for the construction of railway infrastructure is connected — through programmes in the neighbouring countries and EU member states — to Trans-European networks (TEN) that strategically regulate the construction within the community. In the Republic of Slovenia, the construction of railway infrastructure within TEN programmes is carried out on the pan-European traffic Corridors V and X within individual projects for the construction of sections and a number of supporting projects. The technical requirements, deadlines, and other TEN requirements as well as national strategic requirements and financial possibilities of the state represent the basic criteria that should be taken into consideration in setting up a strategic project plan, with optimal project classification achieved through the implementation project portfolio. The current paper has utilised the method of multiple-criteria decision analysis to prepare the portfolio, taking into account the macroeconomic and infrastructural criteria. Consequently, the results represent the basis for the preparation of an optimal financial plan with regard to financing possibilities of the Republic of Slovenia and the European Union. The paper also summarises the research results regarding the formation of the project implementation process of the TEN-T network construction in the Republic of Slovenia.
KEY WORDS: national strategic development, railway infrastructure construction, railway Corridors V and X, project portfolio, multiple-criteria decision analysis, Republic of Slovenia
Functional Analysis of Republic of Croatia for Short Sea Shipping Development
Authors: Bukljaš Skočibušić Mihaela , Jolić Natalija
Published: March 2012

From the aspect of the Republic of Croatia, short-sea shipping has multiple significance. Primarily, the short-sea shipping between the Croatian and Italian coast, diverting of a part of cargo that is transported from the European Union into the countries of south-eastern Balkan via Croatia, reduction in harmful emissions in traffic and increase of traffic in the domestic ports. From the aspect of Europe short-sea shipping refers to the movement of goods and passengers by sea between the ports located in Europe or between these ports and the ports outside Europe that have a joint sea border with Europe. The aim of introducing short-sea shipping are: relief of the burden on the European road routes and shift of transport of cargo and passengers to the maritime transport, improvement of traffic connections and competitiveness of Croatia with the European Union, as well as the connection of the Danube and the Adriatic.
KEY WORDS: short-sea shipping, Republic of Croatia, maritime routes, traffic corridors
Model Approach to Quality Provision of Public Passenger Transport
Authors: Krajnc Roman , Sever Drago
Published: March 2012

Modern approach to transportation system research is based on the system theory. System analysis is relevant. Constant transportation technique and technology devel-opment caused by the need of conformation to the new market conditions is the basis for such an approach. The model approach for resolving the problems of public pas-senger transport is provided in a scientific report. The model of quality of passenger transport comprises the submodels which define relevant measures for the provi-sion of passenger transport quality. The synthesis of sub-model for adoption of quality standards, submodel of pas-senger demands, submodel of operation safety and securi-ty and economic submodel construct the model of quality of public passenger transport (PPT). Its evaluation has been carried out using SWOT analysis.
KEY WORDS: public passenger transport, traffic, lines, network, quality, mobility
Influence of Legislation on Road Traffic Safety
Authors: Rajsman Marijan , Lisicin Georg-Davor
Published: March 2012

The objective of this paper is to analyse road traffic safety in the Republic of Croatia based on the selected indicators which were used by the legislator in bringing the Law on Road Traffic Safety which has been in force since 28 July 2004, and the achieved effects in reaching the desired safety level in the three-year period from 2005 to 2007. The aim of the research is to establish a prognostic trend of the values of the studied indicators in the time period following the enforcement of new legal regulations. Adequate safety indicator values for the respective period were analyzed using the methods of analysis and synthesis, mathematical statistics as well as trend assessment based on the found mathematical prognostic models. Based on the results of this research it was found that the basic hypothesis according to which the implementation of new legal guidelines had to result in positive change in the condition of road traffic safety, failed to be confirmed. A change in the road traffic safety improvement strategy has been proposed as well as a more significant participation and recognition of the profession and science in this field which is of great significance for the society.
KEY WORDS: influence of legal regulations, road traffic safety, effects and tendencies
Reinforcement Learning Technique in Multiple Motorway Access Control Strategy Design
Authors: Veljanovska Kostandina , M. Bombol Kristi , Maher Tomaž
Published: March 2012

An appropriately designed motorway access control can decrease the total travel time spent in the system up to 30% and consequently increase the merging operations safety. To date, implemented traffic responsive motorway access control systems have been of local or regulatory type and not truly adaptive in the real sense of the meaning. Hence, traffic flow can be influenced positively by numerous intelligent transportation system (ITS) techniques. In this paper a contemporary approach is presented. It considers the design philosophy of an optimal and adaptive closed-loop multiple motorway access control strategy. The methodology proposed uses the artificial intelligence technique - known as reinforcement learning (RL) with multiple agents, and applies the Q-learning algorithm. One segment of the motorway network with three lanes in each direction and three motorway entries was designed. The detectors and traffic signals were placed at the entries (ramps). Traffic flows and traffic occupancy on the main line as well as the traffic demand on the motorway entries were taken as input model variables. The output variables referred to the travel speed on the corridor, the total travel time, and the total stop time. VISSIM micro-simulator and direct programming of the simulator functions were used in order to implement the RL technique. The peak hour was chosen for the time of simulation.
The model was tested in two phases. Its effectiveness was compared to ALINEA. It was observed that the proposed strategy was capable of responding both to dynamic sensory inputs from the environment and to dynamically changing environment. The model of the environment and supervision were not required. The control policy changed as response to the inherent system characteristic changes. It was confirmed that the strategy was truly adaptive and real-time responsive to the traffic demand on the corridor.
KEY WORDS: motorway access, traffic flows, control, strategy, artificial intelligence, Q-Learning, simulation
Influence of Society Changes on the Model of Hazardous Goods Road Transportation
Authors: Muha Robert , Sever Drago
Published: March 2012

The transportation of hazardous goods represents an economic activity whose consequences can have serious impact on the safety of transportation, the environment and human health. With the aim of reviewing the elements that affect the activity, this article presents a model for the transportation of hazardous goods of which, generally, there are two forms: the theoretical model for the transportation of hazardous goods, which represents the goal for the establishment of relations on the transportation of hazardous goods services market; and the real model for the transportation of hazardous goods, which represents an adaptation of the theoretical model to the status in a specific localised region. The research, which was conducted as part of the principal author’s Ph.D. thesis, illustrates the exceptional influence of the society changes within a specific country. The theoretical model for the road transportation of hazardous goods is transposed into the real transportation services environment in Slovenia and it presents its transition and incorporation into the common EU transportation service market.
KEY WORDS: transportation policy, model of the road transportation of hazardous goods
Design of River System Deadlock Avoidance Supervisor by Using Petri Net
Authors: Kezić Danko , Gudelj Anita
Published: March 2012

Advanced function of the computer-based river traffic management system should automatically predict and prevent possible conflict and deadlock states between vessels by using adequate control policy (supervisor). This paper proposes a formal method for calculating maximally permissive deadlock prevention supervisor. To model the river system, the authors use a class of Petri net suitable for describing multiple re-entrant flowlines with disjoint sets of resources, jobs and control places, and matrix-based formal method to analyze the system. By using matrix algebra, the structural characteristics of the Petri net (circular waits, P-invariants, critical siphons and subsystem, key resource) have been analyzed and the steps for supervisor design proposed. The first and the second level deadlocks can be avoided by maintaining the number of tokens in the critical subsystems and ensuring that the key resource would not be the last available resource in the system. The derived supervisor has been verified by a computer simulation using MATLAB environment. KEYWORDS: traffic management system, deadlock avoidance, discrete event system, Petri net
An Approach to the Selection of Optimal Transformation Strategy in Seaports
Authors: Đelović Deda , Medenica Mitrović Dijana
Published: March 2012

After theoretical considerations of organizational changes, the research findings were presented in relation to the following: the selection of the optimal model for implementation of organizational changes in the port that is subject of analysis and establishing of the character of the correlation between the organizational changes, the productivity level and the ship service time (components related to cargo handling operations). Through the implementation of AHP (Analytic Hierarchy Process) method, it has been identified that the optimal model for implementation of organizational changes in the studied port is restructuring. Starting from the relevant elements of the process model of productivity improvement, direct interdependency has been identified between the character of organizational changes and the level of productivity per full-time employee in the port, as well as the existence of correlation between the character of organizational changes, productivity level in the cargo handling process ship service time. KEY WORDS: port, organisational changes, AHP method