ALBERT

Description: Almost 50 years ago Robert Dahl maintained “we can […] reasonably hope 1 day to achieve great democratic cities. As the optimum unit for democracy in the 21st century, the city has a greater claim, I think, than any other alternative” (Am Polit Sci Rev 61: 953–970, 1967 ). This article intends to ascertain whether the words of one of the greatest scholars of democracy have had a concrete outcome along the pathways taken by democratic theory and whether, therefore, as was the case in classical theory, real superiority has therefore been restored to the city compared with the other territorial institutions of democracy. In this article we begin with two assumptions, each concerning the theoretical status of democratic theory. The first maintains that a realistic and an idealistic dimension coexist in variable dimensions in theoretical democratic models. According to the second assumption, it can be stated that democratic theory envisages the presence of a local territorial dimension, the importance of which is nevertheless variable in the different theoretical models. The thesis we intend to demonstrate here is that the variable nature of the importance of the local-urban territorial dimension depends on the type of balance created between the idealistic and realistic dimensions of the different models of democracy. Concluding, we aim to theoretically demonstrate why (and at which conditions) the city can become, more and better than any other institutional place, the ultimate arena within which the best results may be achieved for democracy in 21st century.

Description: Background: Finding the current location of a specific utility or oneself in an unfamiliar facility can be difficult and time consuming. The hypothesis tested in this paper is that using the information contained within Building Information Models (BIM) can increase the accuracy of indoor positioning algorithms using context-aware sensing technology. The presented work demonstrates how the integration of passive Radio Frequency Identification (RFID) tracking technology and Building Information Modeling (BIM) can assist indoor localization for potential applications in facilities management for proactive preventative maintenance. Methods: This paper includes (1) developing a framework that utilizes the integration of commercially-available RFID and a building information model; (2) evaluating the framework for real-time resource location tracking within an indoor environment; and (3) developing an algorithm for real-time localization and visualization in a BIM. A prototype application has been developed that simultaneously connects the RFID readers on a maintenance cart, an asset maintenance database and a BIM model. Three multilateralization approaches were compared in the system to use in the algorithm. Testing was conducted in a facility with a corridor that loops around in a rectangle. Results: The goal is to have a system accuracy within 3 m. Results show that fusing BIM with multilateralization techniques for RFID technology can decrease the number of false reads by 64 % versus standalone multilateralization equations. The greatest system accuracy achieved was 1.66 m. Conclusions: Significantly, the results validate the hypothesis that BIM can increase indoor localization accuracy, and show the usefulness of using BIM for indoor localization in addition to real-time visualization.

Description: The present work proposes a new image analysis method for the evaluation of the multi-walled carbon nanotube (MWNT) distribution in a cement matrix. In this method, white cement was used instead of ordinary Portland cement with MWNT in an effort to differentiate MWNT from the cement matrix. In addition, MWNT-embedded cement composites were fabricated under different flows of fresh composite mixtures, incorporating a constant MWNT content (0.6 wt%) to verify correlation between the MWNT distribution and flow. The image analysis demonstrated that the MWNT distribution was significantly enhanced in the composites fabricated under a low flow condition, and DC conductivity results revealed the dramatic increase in the conductivity of the composites fabricated under the same condition, which supported the image analysis results. The composites were also prepared under the low flow condition (114 mm 〈 flow 〈 126 mm), incorporating various MWNT contents. The image analysis of the composites revealed an increase in the planar occupation ratio of MWNT, and DC conductivity results exhibited dramatic increase in the conductivity (percolation phenomena) as the MWNT content increased. The image analysis and DC conductivity results indicated that fabrication of the composites under the low flow condition was an effective way to enhance the MWNT distribution.

Description: This study analyzed the isolation effect for a 15-story reinforced concrete (RC) building with regard to changes in the beam-column stiffness ratio and the difference in the vibration period between the superstructure and an isolation layer in order to provide basic data that are needed to devise a framework for the design of isolated RC buildings. First, this analytical study proposes to design RC building frames by securing an isolation period that is at least 2.5 times longer than the natural vibration period of a superstructure and configuring a target isolation period that is 3.0 s or longer. To verify the proposed plan, shaking table tests were conducted on a scaled-down model of 15-story RC building installed with laminated rubber bearings. The experimental results indicate that the tested isolated structure, which complied with the proposed conditions, exhibited an almost constant response distribution, verifying that the behavior of the structure improved in terms of usability. The RC building’s response to inter-story drift (which causes structural damage) was reduced by about one-third that of a non-isolated structure, thereby confirming that the safety of such a superstructure can be achieved through the building’s improved seismic performance.

Description: Introduction Though studies show that arriving on-time is the service characteristic most valued by the air passengers and passenger service coordinators are consulted in the operation disruptions, passengers rarely drive operational decision-making in the disruption management of an airline. Taking into consideration airlines’ seeking the prevention of losing passengers’ goodwill in situations where the level of service quality (SQ) performed is not as high as the promoted one, this research is focused particularly on an influence of delayed connecting (or in-bound) high-fare passengers on making decisions on onward delays. Operationally seen, connecting passengers are of a particular importance for airlines, since they are already involved in their operations-flow, while becoming in this way the third most important airlines’ aspect of operations, succeeding aircraft and crew. On the other hand, exclusive travellers such as first class and elite-status, contracted corporate members, and business passengers are considered as the high-valuable passengers, who are enough ( financially ) worth to the airline , particularly for to be waited for if they are delayed in arriving with an in-bound flight. Based upon an examination made from the airlines’ operational point of view and for determined prioritization strategy, a Decision Support System (DSS) tool, named DEVOTED DSS Tool, for use in the disruption management of the Airline Operation Control Centre (AOCC) is presented. For assisting the airline operation controllers in decisions on whether to delay the departure of out-bound flights in order to wait for arriving-delayed high-fare passengers from an in-bound flight, an influence of these passengers’ satisfaction on making decisions on onward delays, the passenger segmentation per flight, associated consequences in terms of the Level of Service (LOS) performed by the carrier and the one perceived by the passengers, as well as the accompanying costs are taken into account. Methods The designed tool incorporates the key elements of Human-Centred Design (HCD) relying on a multi-criteria algorithm making-up its decision making process for evaluation of decision options and making suggestion. Being scenario-driven and knowledge-based the tool implements the airline prioritisation policies. Hereby, the level of service quality delivered by the air carrier and the level of service quality expected and perceived by the high-fare passengers are determined quantitatively by employing a created LOS-model which relies on the basic categorization rules of the Kano’s quality model. Results For testing of the tool, two scheduled airlines with two different prioritization strategies and operating on the same flight route between the same origin-destination airports (i.e. city-pairs) are taken. Though the testing is real-world data based, in order to expose a tangible aim and capabilities of the designed tool, the testing scenarios are constructed in such a way to reflect specific borderline operational situations, while emphasizing occurring conflicting decision key criteria. The tool output consists of two components – the LOS quality delivered by the carrier including the delay-costs ( LOS Airline ) and the level of service perceived by the high-fare passengers on both flights ( LOS Passenger ) – which are reflected on the user interface in form of two bars, each consisting of three colours indicating an option as good (green), neutral (yellow) or bad (red). Although the operation controller may take the opposite decision as recommended, the tool is enabled to display the evaluation of consequences of any decision made, while being visualized as a scale-value positioned somewhere on the three- colour-bar. Conclusion Investigating the impact of a passenger-structure on decisions on onward-delays in the every-day flight operations execution, a decision support real-time tool, De laying V IPs O rien ted D ecision S upport S ystem (DEVOTED DSS) was created, implementing (pre-specified) airline prioritisation policy in accordance with the rating of the high-fare passengers-classes importance. The decision solutions’ consequences displayed in the designed form are practical in terms of user-friendly utilization of DEVOTED and are simple and easy to deal with, since being relieved of any digits, data and/or calculations. Aiming at accurately evaluating the impact of operational disruption-decisions on the high-fare passengers, DEVOTED processes the LOS quality which is to be delivered to these passengers, SQ-attributes required/expected by these passengers, number of passengers in each defined passenger-group and the ticket prices purchased, as well as expected costs. For the first time, an introduced juxtaposition of the in-bound and out-bound high-fare passengers of the same cabin-class within connecting flights has been employed as an influencing factor in the decision making process of the airline disruption management. When it is about to make the choice between a monetary benefit and the retention of the reputation of a reliable service provider, the use of the designed tool affords rather objective instead the still occurring intuitive decision making in such disruptions.

Description: Reinforced concrete beams with insufficient shear reinforcement were strengthened using glass fiber reinforced polymer (GFRP) plates. In the study, the effect of the number of bolts on the load capacity, energy dissipation, and stiffness of reinforced concrete beams were investigated by using anchor bolt of different numbers. Three strengthened with GFRP specimens, one flexural reference specimen designed in accordance to Regulation on Buildings Constructed in Disaster Areas rules, and one shear reinforcement insufficient reference specimen was tested. Anchorage was made on the surfaces of the beams in strengthened specimens using 2, 3 and 4 bolts respectively. All beams were tested under monotonic loads. Results obtained from the tests of strengthened concrete beams were compared with the result of good flexural reference specimen. The beam in which 4 bolts were used in adhering GFRP plates on beam surfaces carried approximately equal loads with the beam named as a flexural reference. The amount of energy dissipated by strengthened DE5 specimen was 96 % of the amount of energy dissipated by DE1 reference specimen. Strengthened DE5 specimen initial stiffness equal to DE1 reference specimen initial stiffness, but strengthened DE5 specimen yield stiffness about 4 % lower than DE1 reference specimen yield stiffness. Also, DE5 specimen exhibited ductile behavior and was fractured due to bending fracture. Upon the increase of the number of anchorages used in a strengthening collapsing manner of test specimens changed and load capacity and ductility thereof increased.

Description: Purpose The critical and follow-up headways are the two gap-acceptance parameters which explain the traffic interaction of a minor street vehicle when enters the roundabout, merging into or crossing one or more circulating (major) streams. Several studies and researches provide measurements of critical and follow-up headways from real data at roundabouts. The objective of our research is to synthesize the data from the series of selected studies to interpret variation across the studies. Methods In order to match the research goal, a systematic literature review on estimations of critical and follow-up headways at roundabouts was undertaken. Since several studies and researches developed worldwide were examined, we were able to note that the effect size varied from study to study. Thus the meta-analysis of effect sizes was performed as part of the literature review through the random-effects model. Results After discussing the assumptions of this model, the dispersion in effects across studies was assessed and the summary effect for each of the parameters under examination was computed. Calculations were made both for single-lane roundabouts and double-lane roundabouts, as well as for turbo roundabouts. Conclusions Compared to the results of individual studies, the single (quantitative) meta-analytic estimate provides an accurate and reliable synthesis on the specific issue here addressed, and gives, with greater power of the individual reviewed studies, a comprehensive measure for the parameters of interest.

Description: Purpose This paper aims to evaluate the competitiveness of Iberian seaports through efficiency using an alternative DEA approach (Data Envelopment Analysis) and identifies explicit causes of inefficiency. Methods This paper applying an alternative DEA approach (three stage DEA model) to provide a more useful insight about the cause of efficiency or inefficiency of the seaports. Results and conclusions The average efficiency score under CCR equal to 83.74 meaning that, on average, the seaports analysed could operate at 83.74 % of their current levels while still returning the same output value. Unlike the ranking in terms of cargo throughput, the most efficient Portuguese seaports are Leixões and Setubal and their Spanish peers are Algeciras, Barcelona and Tarragona. This has proven what has been reported in other studies: that seaport efficiency is not necessary influenced by its cargo throughput.

Description: Mode II fracture toughness ( K IIc ) of fiber reinforced concrete (FRC) has been widely investigated under various patterns of test specimen geometries. Most of these studies were focused on single type fiber reinforced concrete. There is a lack in such studies for hybrid fiber reinforced concrete. In the current study, an experimental investigation of evaluating mode II fracture toughness ( K IIc ) of hybrid fiber embedded in high strength concrete matrix has been reported. Three different types of fibers; namely steel (S), glass (G), and polypropylene (PP) fibers were mixed together in four hybridization patterns (S/G), (S/PP), (G/PP), (S/G/PP) with constant cumulative volume fraction ( V f ) of 1.5 %. The concrete matrix properties were kept the same for all hybrid FRC patterns. In an attempt to estimate a fairly accepted value of fracture toughness K IIc , four testing geometries and loading types are employed in this investigation. Three different ratios of notch depth to specimen width ( a / w ) 0.3, 0.4, and 0.5 were implemented in this study. Mode II fracture toughness of concrete K IIc was found to decrease with the increment of a/w ratio for all concretes and test geometries. Mode II fracture toughness K IIc was sensitive to the hybridization patterns of fiber. The (S/PP) hybridization pattern showed higher values than all other patterns, while the (S/G/PP) showed insignificant enhancement on mode II fracture toughness ( K IIc ). The four point shear test set up reflected the lowest values of mode II fracture toughness K IIc of concrete. The non damage defect concept proved that, double edge notch prism test setup is the most reliable test to measure pure mode II of concrete.

Description: A proper initial curing is a very simple and inexpensive alternative to improve concrete cover quality and accordingly extend the service life of reinforced concrete structures exposed to aggressive species. A current study investigates the effect of wet curing duration on chloride penetration in plain and blended cement concretes which subjected to tidal exposure condition in south of Iran for 5 years. The results show that wet curing extension preserves concrete against high rate of chloride penetration at early ages and decreases the difference between initial and long-term diffusion coefficients due to improvement of concrete cover quality. But, as the length of exposure period to marine environment increased the effects of initial wet curing became less pronounced. Furthermore, a relationship is developed between wet curing time and diffusion coefficient at early ages and the effect of curing length on time-to-corrosion initiation of concrete is addressed.