Search

Our aim was to compare the stroke outcomes of a direct transfer (DT) to a thrombectomy-capable center vs. initial care at two local stroke centers: a nearby hospital (NH, 36 km) and a distant hospital (DH, 113 km). Patients who underwent a mechanical thrombectomy were analyzed (February 2017–October 2021), and the outcome was considered favorable if the modified Rankin scale (mRS) score was ≤ 2 at three months. A total of 300 patients were included, 55 of which were transferred from the NH and 58 from the DH. There was a difference in the median (IQR) transfer time of 39 min between the hospitals (149 min for the NH vs. 188 min for the DH, p = 0.003). After adjusting for confounding variables, a secondary transfer from the DH, compared to a DT, was associated with a lower functional independence: mRS score ≤ 2 (OR = 0.37, 95% CI = 0.14–0.97, p = 0.043), without significant differences in the mortality between the groups. These differences were not observed in patients from the NH. Conclusions: A secondary transfer from a distant hospital was associated with a poorer functional outcome at 3 months. This unfavorable outcome was not observed among patients transferred from a nearby hospital. These findings highlight the importance of categorizing the suitability of one transfer model over another based on the proximity of hospitals to the thrombectomy center, but also in accordance with organizational and geographic characteristics that vary within each health region. [ABSTRACT FROM AUTHOR]

Dynamic-radius search, formerly known as sequential search, is an effective neighborhood exploration technique for standard edge-exchange neighborhoods such as 2-opt, 2-opt*, swap, relocation, Or-opt, string exchange, etc. Up to now, it has only been used for vehicle routing problems with a homogeneous fleet and in the single-depot context. In this work, we extend dynamic-radius search to the multi-depot vehicle routing problem, in which 2-opt and 2-opt* moves may involve routes from different depots. To this end, we equip dynamic-radius search with a modified pruning criterion that still guarantees to identify a best-improving move, either intra-depot or inter-depot, with little additional computational effort. We experimentally confirm that substantial speedups of factors of 100 and more are achieved compared to an also optimized implementation of lexicographic search, another effective neighborhood exploration technique using a feasibility-based pruning criterion. As one would expect, better local optima are found on average when allowing inter-depot moves in radius search (positive result). Against intuition, we do however not end up with a better ILS metaheuristic regarding best found solutions, i.e., better average results do not translate into better overall results. We can at least partly explain the latter negative result, which might be useful for other researchers and their attempt to algorithmically optimize their neighborhood exploration procedures. [ABSTRACT FROM AUTHOR]

The goods collection and delivery process often relates to distribution logistics problems. The task is to deliver goods from warehouses to customers under specific circumstances. Efforts to optimize the process are largely aimed at reducing overall costs of goods transportation. Among the prominent algorithms for solving the basic type of the delivery (or collection) problem, which includes a single depot and a homogeneous vehicle fleet, is the algorithm developed by Clarke and Wright in 1964. This algorithm minimizes transportation costs by maximizing the savings achieved through merging multiple routes into one. This paper primarily aims to solve the pickup and delivery problem where the goods must be delivered and empty packaging collected in a single process. The request of a customer can be routed from the depot or from another customer. Similarly, the destination of the request may be the depot or another customer. Unlike the original version of the Clarke and Wright algorithm, the initial routes are created to satisfy delivery orders, and therefore, the same customer can occur in multiple routes. Consequently, a situation may arise in which two routes containing one or more common vertices must be combined during the calculation. Furthermore, these vertices need not be the outermost vertices of the routes. This situation cannot be addressed by using the original version of the Clarke and Wright algorithm, and that is why we propose its modification. Merging routes through inner vertices means that the cost savings depend on the configurations of the routes, and therefore, they cannot be calculated a priori. Instead, the dynamic savings matrix must be used. [ABSTRACT FROM AUTHOR]

The development of the hydrogen-fueled vehicle industry needs a mature hydrogenation network to provide a guaranteed source of hydrogen in the future. We propose a dynamic hydrogen supply network optimization model under demand uncertainty. The model incorporates the dynamic characteristics of the network, takes into account the linkages of units within the network as well as the hydrogenation network between cycles. Hydrogenation networks can be planned over multiple cycles and allow for capacity expansion of hydrogen production and refueling stations, and shifts in the way hydrogen is transported between sites. Robust optimization is used to deal with demand uncertainty. In the results of the case study obtained, resources within the network were fully utilized, costs within the network show economies of scale; the average resource utilization rate at each site reached 85.6 %; and the rate of meeting user demand reached more than 98.5 %. A hydrogenation network with sustainable operations was formed. [Display omitted] • The dynamic characteristics of the network over time is considered. • A hydrogenation network with sustainable operations is formed. • Stations and hydrogen transportation demonstrate economies of scale. • A robust optimization model is established to deal with uncertainty. • Maximize network resources while hydrogen demand is effectively met. [ABSTRACT FROM AUTHOR]

The document titled "Reviewers" acknowledges and expresses gratitude to individuals who reviewed manuscripts submitted to the Journal of Urban Planning and Development from July 1, 2022, to June 30, 2023. The list includes a diverse range of reviewers from various institutions and countries, such as Iran, Egypt, Nigeria, India, China, and the United States. The reviewers' contributions are recognized and appreciated for their valuable input in the field of urban planning and development. [Extracted from the article]

Vehicular ad hoc networks (VANETs) establish the connection between the vehicles through wireless communication. This link stability is significant for achieving traffic safety and traffic efficiencies. But sharing security messages in the mobile environment is very complex because of the excessive speed of the vehicles, unsteady communication links, and geographically constrained topologies. A Roadside Unit is vital for vehicle connection with the transportation center. We proposed Tri-Parametric FUZZY logic (TP-FUZZY) for establishing the stable connection in VANET. The proposed Tri-Parametric FUZZY Logic effectively addresses the complexity of the vehicles' excessive speed, etc. We have considered the combination of normal-speed vehicles containing a high data rate and the shortest distance for forming the clusters. The cluster head (CH) concept is implemented to monitor and control the entire mechanism. The FUZZY Logic executes the automatic selection of the next CH if the current CH triggers exit from the cluster. It ensures the overall cluster mechanisms stability. The proposed simulation results prove that Tri-Parametric FUZZY logic performance in the aspect of Packet delivery ratio, Dynamic cluster head changes, Routing overhead, End to end delay and Energy consumption is more effective than the other existing mechanisms. Thus, the proposed TP-FUZZY is a prominent solution for establishing reliable link connectivity in the VANET. [ABSTRACT FROM AUTHOR]

An electric scooter sharing (ESS) service offers improved convenience by providing accessibility to public transportation stations and mobility for short-distance trips. However, with the growing global popularity of ESS services, concerns related to safety and accidents have also increased. Previous studies explored the factors impacting preferences for ESS services; however, few have considered ways to enhance safety and convenience for users. Therefore, this study investigated the factors that influence people's choice of ESS service for enhancing safety and convenience. Data was collected in Seoul, Korea, and a latent class model was developed, allowing us to estimate the willingness-to-pay (WTP) of various attributes. The estimation results revealed that the "Exclusive e-scooter lane" attribute was the most preferred, followed by "provision of real-time driving information." The WTP for "Exclusive e-scooter lane" was 47.1% above the base fare. In the estimation results of the class membership model, the preferred attributes were different depending on the class characteristics. The study further revealed variations in WTP for safety and convenience among users and non-users, as well as among non-users depending on their intent to use the ESS service. Furthermore, the proposed attributes constituted factors that affect the safety and convenience of ESS users, and that users were willing to pay an additional cost for them. • Investigating the preferences of ESS service users is essential for establishing operation strategy. • We identified factors with potential positive impact on ESS safety and convenience. • 1000 potential users were surveyed and a latent class model was constructed. • Users were most willing to pay for exclusive e-scooter lane. • Heterogeneity analysis: age and intention to use ESS varied willingness to pay. [ABSTRACT FROM AUTHOR]

This study assessed the effect of intentional foraminal enlargement on the foramen and the apical root canal morphology. Sixty mesial roots of mandibular molars were scanned by micro-computed tomography. Their apical foramina were photographed with a stereomicroscope before and after preparation. Three groups were formed (n = 20) according to the working length (WL). G-1: foramen - 1 mm; G0: foramen; and G+1: foramen + 1 mm. Each group originated 2 subgroups (n = 10): G-1: Buchanan's patency (size 10 K-type file) and foraminal debridement (sizes 20, 25 and 30 K-type files); G0 and G+1: rotary foraminal enlargement (ProDesign S size 25/.08) or reciprocating foraminal enlargement (R25). The area, perimeter, transportation, and noninstrumented walls of the foramen were evaluated. The root canal transportation and the centering index of preparation at 1, 3 and 5 mm from the foramen were also assessed. Data were compared statistically (α = 5%). The instruments used at the foramen and 1 mm beyond promoted foraminal enlargement and transportation. Regarding NIW, there was no difference between mechanized foraminal enlargements performed at the foramen or 1 mm beyond, similar to the manual foraminal debridement group (P >.05). There was no difference in transportation and centralization at 1-, 3-, and 5-mm apical levels, regardless of the instrumentation systems. Mechanical preparation at the foramen, or 1 mm beyond, resulted in foraminal enlargement, transportation and were not able to touch all root canal walls that delimit the foramen. [ABSTRACT FROM AUTHOR]

This research examines canal transportation and centering ability of single‐file systems when operated in continuous rotation or reciprocation. Sixty J‐shaped resin blocks were used. The specimens were divided into two main groups (n = 30). Then, based on the motion used to operate the instruments, each group was subdivided into two subgroups (n = 15). Group A1: One Curve/rotation, Group A2: One Curve/clockwise reciprocation, Group B1: WaveOne Gold/Reciprocation, Group B2: WaveOne Gold/counter‐clockwise rotation. Pre‐ and post‐instrumentation images were obtained using digital microscope. Canal transportation was measured at five levels. A non‐significant difference (p > 0.05) resulted between two motions at all levels. However, group A1 showed significantly less transportation at levels 3 and 4 (p ≤ 0.05), also more centered preparation at level 4 (p ≤ 0.05) than group B1. Within the limitations of this study, the apical transportation and centering ability of single‐file systems are unaffected by different kinematics. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

China has the world's longest high-speed rail (HSR) network, marked by dense transportation and complex operations. However, frequent train use coupled with extreme weather conditions has led to rising subgrade issues. Existing railway defect records suffer from inconsistency, hindering direct applicability. Currently, there is a lack of a relevant dataset dedicated to HSR subgrade defects. To bridge this gap, we developed a comprehensive georeferenced dataset that encompasses defect records extracted from peer-reviewed literature published between 1999 and 2023 in China. Rigorous quality control procedures were implemented to eliminate duplicate data and ensure the accuracy of the dataset. The dataset consists of georeferenced records for eight different defects, spanning across 661 locations and categorized at various scales, ranging from provinces to townships. The most commonly reported defect types include subgrade settlement, frost damage, uplift deformation, and mud pumping. This dataset provides a comprehensive map of historical subgrade defects affecting high-speed railways in China. It could facilitate operational risk assessments and the prediction of subgrade performance. [ABSTRACT FROM AUTHOR]

Emergencies intensify existing vulnerabilities and create new ones for people in their impact areas. In the case of transportation, for example, disasters have the capacity to isolate individuals from the services on which they rely not for only their health and wellbeing, but for their very lives. This paper discusses the Regional Alliance for Resilient and Equitable Transportation (RARET) — a coalition-based model created to address non-life-saving transportation coordination needs during emergencies. RARET focuses on the provision of lifesustaining transportation, serving vulnerable individuals who may require first-responder assistance if their unaddressed needs remain unmet. Using examples from the COVID-19 pandemic as well as seasonal and regional disasters, the paper highlights how leveraging a coalition built to break down the sector and geographical silos leads to better outcomes for the public and bolsters regional resiliency. The paper underlines how the novel nature of RARET delivers ongoing process improvements via a new emergency transportation provider network. Lastly, the paper suggests methods to adapt this model to other jurisdictions. [ABSTRACT FROM AUTHOR]

Because logistics companies usually have multiple depots to serve their many dispersed customers, multi-depot vehicle routing problem (MDVRP) has gained significant research attention. To solve an MDVRP model, this paper develops a hybrid ant colony optimization based on a polygonal circumcenter (BPC-HACO). Furthermore, because ACO has been found to fall easily into the local optimum, simulated annealing and three local optimization operations are introduced to encourage the ACO to improve the algorithm's optimization ability. Finally, MDVRP benchmarks and data sets of other papers are employed to verify the effectiveness of the BPC-HACO in solving MDVRP (In 23 instances, BPC-HACO finds 14 BSKs, and 3 results are better than the BSKs), MDVRP with distance constraints (Compared to other papers, the route length is reduced by an average of 17.94%) and dynamic MDVRP (In 10 instances, BPC-HACO finds 3 BSKs, and 2 results are better than the BSKs). Finally, fitness landscape analysis has been applied to analyze the structural features of MDVRP to choose the most appropriate algorithm for MDVRP. [ABSTRACT FROM AUTHOR]

Flexible and precise manipulation of droplet transport is of significance for scientific and engineering applications, but real-time and on-demand droplet manipulation remains a challenge. Herein, we report a strategy using light for the outstanding manipulation of binary droplet motion on a high-energy surface and reveal the underlying mechanism. Upon irradiation to a substrate by a focused light beam, the substrate can provide a localized heating source via photothermal conversion, and a binary droplet can be flexibly transported on a high-energy surface with free contact-line pinning, exhibiting light-propelled droplet transport. We theoretically showed that the surface tension gradient across the droplet interface resulting from the localized photothermal effect is responsible for actuating droplet transport. Remarkably, the high reconfigurability and flexibility of light allowed for binary droplet transport with dynamically tunable velocity and direction as well as arbitrary trajectory assisted by 2D channels on a high-energy surface. Complex droplet transportation, controllable droplet coalescence, and anti-gravity motion were realized. The promising applicability of this light-fueled droplet platform was also demonstrated by directional transport of biosample droplets containing DNA molecules and cells, as well as successional microreactions. [ABSTRACT FROM AUTHOR]

This paper studies the multiple geosynchronous spacecraft refueling problem (MGSRP) with multiple servicing spacecraft (Ssc) and fuel depots (FDs). In the mission scenario, multiple Ssc and FDs are parked in the geosynchronous Earth orbit (GEO) initially. Ssc start from FDs and maneuver to visit and refuel multiple GEO targets with known demands. These capacitated Ssc are expected to rendezvous with fuel-deficient GEO targets and FDs for the purpose of delivering the fuel stored in FDs to GEO targets. The objective is to find a set of Pareto-optimal solutions with minimum fuel cost and mission duration. The MGSRP is a much more complex variant of multidepot vehicle routing problems mixing discrete and continuous variables. A two-nested optimization model is built. We propose a new multiobjective hybrid particle swarm optimization to solve the outer-loop problem, and the design variables are the refueling sequence, task assignment, time distribution, and locations of FDs. In the inner-loop problem, branch and bound method is used to find the optimal decision variable for a given outer-loop solution. Finally, numerical simulations are presented to illustrate the effectiveness and validity of the proposed approach. [ABSTRACT FROM AUTHOR]

In the process of promoting the use of the Centralized Traffic Control System 3.0(CTC 3.0) systems, the process management function for the operations of receiving and departing trains is particularly focused on and valued by stations due to the wide coverage of job positions and the need to coordinate multiple such positions in order to facilitate the smooth flow of the process for receiving and departing trains. This paper analyzes the business process of receiving and departing train operations in the station's transportation production process, and combines it with the CTC 3.0 process management function to explore a CTC 3.0 multi-job-position coordination technology scheme based on a wireless private network. The aim is to achieve digitization in the management of the receiving and departing train operation process at CTC 3.0 stations, thereby reducing the workload of station personnel in future practice. [ABSTRACT FROM AUTHOR]

Electric buses have been vigorously promoted and implemented in major countries worldwide and have generated a huge demand for charging stations. Optimizing the daily charging experience of electric buses, adapting the daily operation scheduling, improving the utilization rate of charging stations, reducing the load on the power grid, and improving the operation efficiency of electric bus line networks require the reasonable layout of the charging stations. In this study, public transportation charging station layout and siting is the research object. We summarize the progress of analysis methods from the charging station and vehicle sides; introduce related research on the planning and layout of charging stations based on optimization models, including cost analysis and siting and layout for electric bus systems; summarize the data-driven station planning and siting research; and provide an overview of the current charging demand estimation, accuracy, and charging efficiency. Finally, we address the problems of the charging demand estimation accuracy, the mismatch between the charging station layouts for electric buses, and the charging demand on a long time scale. We suggest that research be conducted on data fusion for the temporal and spatial refinement of charging demand prediction in the context of the electrification of public transportation systems and the big data of telematics. [ABSTRACT FROM AUTHOR]

Multi-robot cooperation is a typical application of multi-robot system, which has strong potential applications in many special occasions. However, few scholars have considered cooperative optimization transportation from the perspective of optimization. This paper investigates the cooperative transportation optimization problem for multiple mobile robots with kinematically redundant manipulators. First, a discrete-time distributed optimization algorithm with fixed step size is proposed to achieve linear convergence. Second, by introducing a rotation variable into the optimization problem, the joint angular velocity of manipulator and the velocity of moving platform change more smoothly. Third, a virtual leader-follower transport strategy is used in this paper to improve the stability of the multi-robot system. In the physical experiment, the trajectory of each end-effector matches the expected trajectory, and the center trajectory of the transport object almost coincides with the virtual leader trajectory with acceptable error. Moreover, the simulation and physical example are provided to demonstrate the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

A personal narrative is presented which explores the author's experience of witnessing the creation of the fourth day of "The Satin Shoe" by the Renaud-Barrault Company at the Orsay Station in 1972, reflecting on the surreal atmosphere and transformative power of theater in unexpected locations.

Problem definition: We consider pricing of services with strategic customers who have heterogeneous delay costs motivated by transportation systems. Customers are strategic decision makers who weigh the reward from the transport service against the waiting cost for the vehicle at a transportation station. Customers arrive at the station according to a Poisson process, and the vehicle visits the station according to a renewal process. We analyze the optimal price and the equilibrium for different levels of information available to customers. Methodology/results: We represent the service system as a stochastic clearing process, heterogeneity in delay cost as a random variable, and heterogeneity in rewards as a positive affine transformation of delay cost. For each information level, we identify the equilibrium behavior of customers and solve the revenue-maximization problem based on this equilibrium. The equilibrium turns out to be unique in each case, and it is of a threshold form in the sense that for each value of the information, it is best to join either for all types of customers, only for those who are sufficiently price sensitive, only for those who are sufficiently delay sensitive, or for none. The optimal fee is also unique in nontrivial cases. This enables us to perform comparisons across different information structures. Managerial implications: The effect of heterogeneity depends highly on model parameters as well as the available information. For a fixed fee, an increase in heterogeneity has a positive overall impact on the customer population, whereas the effect on the revenue can be positive (slow service at a high fee) or negative (fast service at a low fee). Unlike with fixed fee, for the optimal fee, an increase in heterogeneity can have a negative overall effect on customers. Ignoring heterogeneity can lead to a substantial opportunity loss for the system. Funding: A. Manou was supported by AXA Research Fund. P. G. Canbolat was supported by Marie Curie Career Integration Grant from the European Union's Seventh Framework Programme (RISK) [FP7-PEOPLE-2013-CIG, Proposal No. 618853]. Supplemental Material: The e-companion is available at https://doi.org/10.1287/msom.2021.0116. [ABSTRACT FROM AUTHOR]

There are many kinds of switches lying midway in receiving-departure tracks at railway stations. For some special switches lying midway in receiving-departure tracks, the existing technical conditions for switches lying midway in receiving-departure tracks cannot meet the actual application requirements. This paper introduces the application scenarios for different types of switches lying midway receiving-departure tracks in actual projects, and analyzes what special treatments computer based interlocking needs to provide for each application scenario on the basis of the standard protection circuit for switches lying midway in receiving-departure tracks, to ensure the safety of train operation while meeting the needs of transportation operations at stations. [ABSTRACT FROM AUTHOR]

Aim: To assess the canal transportation and centering ability in the mandibular first molars' curved mesiobuccal canals after instrumentation with file systems XP endo Shaper, self-adjusting File (SAF), Hyflex EDM, Pro Taper NEXT, WaveOne Gold, and K files with the help of Cone-Beam Computed Tomography (CBCT). Materials and Methods: Ninety recently extracted mandibular first molars with mesiobuccal roots that had a 25-30 degree canal curvature were assessed. Following preoperative CBCT scans, teeth were allocated randomly to six experimental groups of fifteen. After preparation with XP endo Shaper, SAF, Hyflex EDM, Pro Taper Next, WaveOne Gold, and K files, post-instrumentation scans were taken using same parameters as pre operative scans. At 3 mm, 6 mm, and 9 mm from the apex, samples were assessed for canal transportation and centering ratio. Results: Apical transportation was least for XP endo Shaper as compared to other groups except SAF and the results were statistically significant. K file showed the highest apical transportation toward the lateral wall of the root canal. XP endo Shaper was better in maintaining centering ability of middle and apical third of canal and SAF was better in maintaining centering ability of coronal third. Conclusion: In root canal preparation, least apical transportation and better centering ability with XP endo Shaper than other file systems compared. K file showed the highest transportation. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to compare canal transportation and centering ability of different nickle titanium systems using Cone beam computed tomography in curved canals. Materials and Methods: Ninety mandibular molars with angle of curvature ranging from 10°-40° were randomly allocated into six experimental groups containing 15 teeth in each group. Preinstrumentation scans were taken with CBCT with constant exposure parameters before and after instrumentation. Six grouped specimens were instrumented with Wave One, Twisted File, Hyflex CM, K3XF, ProTaper Next, NeoNiTi file respectively. Post instrumentation the specimens were scanned by CBCT to obtain postoperative images. The amount of root canal transportation and centering ability of the instrument were determined. Statistical analysis on collected data was performed using One way analysis of ANOVA, and post-hoc Tukey test (p<0.0.5). Results: K3XF group showed significantly higher transportation values in the apical third (2mm) than TF group (p=0.01) and Hyflex CM group (p=0.03). The coronal transportation values are higher than the apical values but with no significant difference between them (p>0.05). There was no significant difference in centering ratio values between the six groups (p>0.05) at any of the level. Conclusion: All the file systems can be safely used, showing satisfactory preservation to the original canal shape with preference of TF files. [ABSTRACT FROM AUTHOR]

Copyright of Corrosion & Protection in Petrochemical Industry is the property of Corrosion & Protection in Petrochemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The rapid development of urban above- and underground transportation has brought an increasing number of deep foundation pit projects that close to existing urban viaducts. Excavation of the deep foundation pit projects leads to soil movement around the pile foundation, which adversely affects the adjacent existing pile foundation and seriously threatens the operation safety of the adjacent existing viaduct. In this paper, the three-dimensional numerical model of foundation pit excavation, viaduct, and pile foundation was established by using the MIDAS GTS against the background of the basement foundation pit project in the new Guangzhou Baiyun Station comprehensive transportation hub building, production, and life complex, where the interaction between foundation pit excavation and viaduct pile foundation was simulated. The influence of various excavation-related factors and different parameters of the pile foundation on lateral displacements of the pile body adjacent to the existing pile foundation was analyzed. The variables controlled in the numerical model included the different excavation depths of the foundation pit, the distance between the excavation surface and the adjacent pile foundation, the spatial effect of different excavation sequences, the diameter of the pile that adjacent to the existing pile foundation, and the elastic modulus of the bored occlusal pile support structure. The results indicated that the lateral displacement of the pile body of the bridge pile foundation was significantly affected by the excavation of the deep foundation pit. The excavation depth exerted the greatest influence on the lateral displacement of the pile foundation, followed by the distance between the pile foundation and the excavation surface, the excavation sequence of the foundation pit, and the elastic modulus and the diameter of the bored occlusive pile support structure. Among them, the pile foundation located at the corner of the foundation pit was negligibly affected by these influencing factors. The findings in this study can provide valuable experiences for similar projects. [ABSTRACT FROM AUTHOR]

The efficiency of bulk solid and general cargo terminals, where ore, grain, and many raw materials are handled, plays a crucial role in socioeconomic development and lays the groundwork for reasonable trade costs. This study evaluates the relative performance of drybulk and general cargo terminals in Türkiye with interval data envelopment analysis (DEA). The dataset consists of 21 terminals operated by private companies for 2018-2021 and has been transformed into an interval form to apply interval DEA to imprecise data. The results imply that the efficiency levels of dry-bulk and general cargo terminals in the Marmara and Mediterranean tend to increase. It can be inferred that the average efficiency level of the Black Sea terminals has remained stable over the years, and the loss of efficiency in the Aegean is remarkable. The application of the Interval DEA in evaluating the efficiency of dry-bulk and general cargo terminals in the case of imprecise data can contribute significantly to the seaport efficiency literature. [ABSTRACT FROM AUTHOR]

logistics occupies an important place in production activities and directly affects the duration of production and product quality. Considering the limited number of studies in the literature on production logistics, which is so important, it is seen that the studies are related to the determination of storage strategies, selection of storage vehicles, structuring of material transport movements, selection of material transport vehicle types, cellular layout, structuring of intracellular and intercellular movements. The use of fuzzy and weighted fuzzy information axiom, which is a fuzzy-based selection approach, for transport activities in industrial cells will be a new study in the literature. The information axiom, which is included in the design methodology with axioms, was used to determine the simplest internal logistics transportation method. An application study was carried out in the factory of an automotive supplier company. The most suitable option among alternative transport methods with different criteria was determined by applying fuzzy information axiom and weighted fuzzy information axiom methodologies. With these approaches, it has been tried to find the simplest and most efficient cell feeding method that provides the most customer expectations. The differences between the current internal logistics transportation method and the proposed lean internal logistics transportation method are given. In order to help decision makers, make decisions without hesitation, the study has been strengthened with sensitivity analysis. [ABSTRACT FROM AUTHOR]

An urban subway network system is a complex public transportation system. To compare rail transit braking digital command control strategies based on neural network, this article analyzes and studies the characteristics of subway vehicle driver controllers and their design methods from three aspects: mechanical, electrical and software-assisted design. The learning rule of the BP neural network is called the mentor system learning rule, which is a kind of error-correcting algorithm. In the learning and training process, the expected output value needs to be given. The weights and thresholds of the BP neural network are optimized by selecting the parameters of the SA algorithm. The search method of SA is heuristic, and it has the following advantages: The selection of the initial solution does not affect the optimal solution. The simplified model extracts the core data processing individual analysis. In this paper, the physical data are extracted from the physical entity operation process for analysis, and the twin model is established to extract the twin data for analysis. This paper uses the characteristics of physical data to test the modeling effect and utilizes the twin data to carry out algorithm experiments on physical data. The ultimate goal is to use twin data to predict the state information of physical entities. The network error in the scheme designed by the article is 6%. The smooth implementation of this research constitutes an important reference for the design of subway train network control systems in other cities in China. Therefore, this research has great application value. [ABSTRACT FROM AUTHOR]

The adoption of all-electric vehicles (EVs) has grown rapidly in the transportation industry, particularly for urban parcel deliveries. However, the limited driving range of EVs and the high investment cost of establishing charging infrastructures are still the holdbacks to routing these EVs. In this paper, we present the vehicle routing problem of a mixed fleet of EVs and conventional vehicles (CVs) via intermediate depots as an alternative strategy to address the challenges, with CVs delivering parcels from the central depot to intermediate depots and EVs delivering parcels from intermediate depots to customers. In addition, we propose an intelligent dispatching scheme to allow EVs to be used for multiple routes. A two-phase approach is developed to first cluster the customers to the intermediate depots and then route the mixed fleet. The strategy is implemented for both small- and large-sized instances, and the results show that using an intelligent dispatching scheme can significantly reduce the number of EVs used. Furthermore, the use of smaller-range EVs is also investigated., and a discussion of potential implementation issues is provided. [ABSTRACT FROM AUTHOR]

The second part of this two-part study presents the public transport relations of the districts in the rural areas in the relation between the given settlement and its own district center. This study examines, inter alia, that if a settlement within a given district is not attracted to its own district center, which settlement fulfils the role of the center in public transportation. To answer this question, the author presents more complex methods (eg. Zimpel index), too. At the end of the study, the author also determines the real public transport catchment areas with the help of the samples drawn on the basis of the methods described above. [ABSTRACT FROM AUTHOR]

Urban rail transit is an essential part of the urban public transportation system. The reasonable spatial data visualization of urban rail transit stations can provide a more intuitive way for the majority of travelers to arrange travel plans and find destinations. The map service of rail transit stations generated by data visualization has gradually become indispensable information guidance in the rail transit system. The existing map service icons block each other when the scale changes, and new stations cannot be displayed dynamically when users drag the map. This paper uses filtering and sorting methods to dynamically query and visualize the relatively more important transportation stations within the users' visible range, so as to solve the above problems and provide people with better transportation services. Our method introduces three constraints: spatial diversity, time-sharing passenger flow analysis and whether it is a transit station, and calculates the scores of constraint relationships of feature objects to evaluate stations. On the basis of the skyline query, the scores of feature objects are combined and sorted to obtain an ordered object set of the most interesting k points(top-k POIs), and the rail transit stations are dynamically retrieved and visualized. Before sorting POIs, we filter out POIs that need to be fitted, so that only the k most representative POIs in the currently visible range are displayed. When the map scale changes, the displayed POIs are updated. Finally, through the statistics of efficiency calculation of this method under different scales and centers, combined with users' evaluations, it was proved that our method could better display critical information and improve user experience. [ABSTRACT FROM AUTHOR]

This paper considers the multi-depot vehicle routing problem with object alternation. We propose a formal statement of the problem with two types of objects and a mathematical model with two blocks of Boolean variables. First, the model is studied without gathering vehicles (mobile objects). Then, a special object (a single collection point) is introduced in the model. We show additional constraints of the mathematical model with this object. Special attention is paid to the condition of no subcycles. This condition is considered based on the adjacency matrix. Five greedy algorithms are proposed for solving the problem, two of which are iterative. One of the greedy algorithms is given a probabilistic modification based on the randomization of variables (an adaptive algorithm). Finally, the proposed algorithms are compared in terms of the average value of the objective function and the running time in a computational experiment. Also, the results of another experiment—the parametric tuning of the adaptive algorithm—are presented. [ABSTRACT FROM AUTHOR]

From the beginning of aviation background to the nowadays, people's demands and needs have also changed with the changes in their lifestyles and technological developments. In this process, airports show a change towards commercialization and urbanization by getting rid of traditional practices under increasing competition conditions. These changes and developments lead airports to seek new applications that will increase their revenues. Now, airports appear as both centers that establish transportation and centers that perform entertainment, culture-arts, tourism, technology, logistics, service and production activities together. Airports have transformed from a traditional business model to a commercialized business model and an urbanized business model in the process. This transformation has also led to diversification in airport revenue sources. When the aviation-based income sources of traditional airports are examined, it is seen that the most important income sources are aviation incomes. In commercial and city airports, it is seen that the share of non-aviation income sources is important in addition to aviation revenues. Within the scope of the study, the top 10 airports in 2021 according to the Skytrax ranking were examined. In the study, data were collected by making use of secondary data sources as a result of annual reports published by airports and literature review. The data obtained were analyzed by content analysis, one of the qualitative research methods. The business models of the airports that are the subject of the study are presented and the income structures that change and differentiate under intense competition conditions are explained. According to the conclusions of the article, the revenues of the airports examined were collected under three main headings as revenues from technological, social and sustainability activities. [ABSTRACT FROM AUTHOR]

Air transportation is a complex system characterized by a plethora of interactions at multiple temporal and spatial scales; as a consequence, even simple dynamics like sequencing aircraft for landing can lead to the appearance of emergent behaviors, which are both difficult to control and detrimental to operational efficiency. We propose a model, based on a modulated Markov jitter, to represent ordinal pattern properties of real landing operations in European airports. The parameters of the model are tuned by minimizing the distance between the probability distributions of ordinal patterns generated by the real and synthetic sequences, as estimated by the Permutation Jensen–Shannon Distance. We show that the correlation between consecutive hours in the landing flow changes between airports and that it can be interpreted as a metric of efficiency. We further compare the dynamics pre and post COVID-19, showing how this has changed beyond what can be attributed to a simple reduction of traffic. We finally draw some operational conclusions and discuss the applicability of these findings in a real operational environment. [ABSTRACT FROM AUTHOR]

Purpose: A successful root canal preparation is to remove infected tissue and to obturate the canal three-dimensionally. The present study aimed to evaluate the centering ability of Protaper Ultimate and RevoS+ rotary file systems in curved canals of printed mandibular first molars by using micro-computed tomography (micro-CT). Materials and Methods: In this study, 16 mandibular molar teeth were printed from resin with 45° mesial root curvature. The instrumentation procedure was performed according to the specified groups, either Protaper Ultimate or RevoS+. The pre-and post-preparation images were repositioned in all three spatial planes by DataViewer. All images were imported into the CTAn software for the calculation of the centering ability and transportation values. Results: The results showed no significant differences between the Protaper Ultimate and RevoS+ groups in terms of the centering ratio in the most inclined part of the canal. There were also no significant differences between the groups in canal transportation. (p>0.05) Conclusions:Protaper Ultimate and RevoS+ rotary file systems showed similar ability in centering ratio and canal transportation in curved canals from printed mandibular molars. This study reported that both systems provide a safe preparation in clinically curved root canals. [ABSTRACT FROM AUTHOR]

Intelligent transport systems are used in various transport systems, among which a special place is occupied by crewed autonomous transport systems such as space stations for deep space habitation. These objects have a complex and critical requirement for life support systems (LSSs) to maintain safe and habitable conditions for the crew in the isolated environment. This paper explores the different architectural options for life support systems (LSSs) in autonomous transport systems, specifically focusing on space stations. Three alternative LSS architectures are discussed: Open LSS (OLSS), Closed LSS (CLSS), and Mixed LSS (MLSS). Each architecture has its own advantages and disadvantages. OLSS relies on external resource delivery, reducing initial costs but increasing dependence on resupply missions. CLSS operates autonomously, generating resources onboard, but has higher initial costs and technological complexity. MLSS combines external delivery and onboard generation, providing flexibility and adaptability. The material emphasizes the importance of cost-effectiveness analysis at the early stages of design and identifies the boundary values of mission duration that determine the most effective LSS architecture choice. The material highlights the significance of striking the right balance between cost and performance to develop intelligent ecosystems of LSS for space stations and other autonomous transport systems. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Economía (Universidad Autónoma de Yucatán) is the property of Universidad Autonoma de Yucatan, Facultad de Economia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim: The objective of this study was to evaluate and compare canal transportation (CT) and centering ability (CA) in the curved canals prepared using HyFlex CM (HCM) and TruNatomy (TN) rotary file systems with the help of cone-beam computed tomography (CBCT). Materials and Methods: Forty extracted single-rooted mandibular premolars with 10°-30° of curvature were selected and divided into two groups. In Group 1, the canals were prepared with HCM files (Coltene Whaledent) and in Group 2 the canals were prepared with TN Prime rotary files (Dentsply Sirona). Pre- and postinstrumentation scans were performed at the same position using CBCT to evaluate CT and CA at three levels 3 mm, 6 mm, and 9 mm from the apex and were compared using CBCT software (On Demand 3D software). Statistical Analysis Used: The two groups were statistically analyzed with Mann-Whitney U-test. Results: There was no significant difference among the tested groups regarding the canal centering ratio (P > 0.05). At 6- and 9-mm levels, there was no significant difference in CT among the two groups (P > 0.05). However, at 3 mm from apex, there was a statistically significant difference (P = 0.006) with TN files exhibiting lesser CT. Conclusion: Both the file systems respected the canal anatomy, although in the apical third, TN files exhibited better results. Hence, this file system can be considered for instrumentation of canals with moderate apical curvatures. In regard to CA, no significant differences were found among the file systems. [ABSTRACT FROM AUTHOR]

Copyright of AIN Journal is the property of Arab Institute of Navigation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Art-Sanat Journal / Art-Sanat is the property of Art-Sanat and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A resilient transportation hub complex affected by a disturbance can maintain minimum performance and rapidly resume operations, while dealing with growing service demands imposed by the unfolding disturbance management. To strengthen the disturbance response ability and achieve postdisturbance rapid recovery, this paper proposes a hybrid approach that integrates a theoretical framework, failure model, and restoration model to assess the resilience of the streamline network of the transportation hub complex. In the resilience assessment framework, system performance is chosen as the key proxy for resilience, which is measured based on a service performance index. Subsequently, a failure model is designed to determine the service performance loss of a streamline network following a disturbance. To obtain maximum service performance, we propose a restoration model that integrates an optimal recovery sequencing strategy and a load redistribution strategy. A test example is used to demonstrate the applicability of the proposed approach. This approach can be used as a decision tool to estimate streamline network resilience and provide useful references for developing future policies. [ABSTRACT FROM AUTHOR]

Motivated by express and e-commerce companies' distribution practices, we study a two-echelon electric vehicle routing problem. In this problem, fuel-powered vehicles are used to transport goods from a depot to intermediate facilities (satellites) in the first echelon, whereas electric vehicles, which have limited driving ranges and need to be recharged at recharging stations, are used to transfer goods from the satellites to customers in the second echelon. We model the problem as an arc flow model and decompose the model into a master problem and pricing subproblem. We propose a branch-and-price algorithm to solve it. We use column generation to solve the restricted master problem to provide lower bounds. By enumerating all the subsets of the satellites, we generate feasible columns by solving the elementary shortest path problem with resource constraints in the first echelon. Then, we design a bidirectional labeling algorithm to generate feasible routes in the second echelon. Comparing the performance of our proposed algorithm with that of CPLEX in solving a set of small-sized instances, we demonstrate the former's effectiveness. We further assess our algorithm in solving two sets of larger scale instances. We also examine the impacts of some model parameters on the solution. [ABSTRACT FROM AUTHOR]

This paper studies the distribution of emergency relief for electric vehicles (EVs), which considers energy saving, multi-depot, and vehicle routing problems with time windows, and the named energy saving-oriented multi-depot vehicle routing problem with time windows (ESMDVRPTW). Our aim is to find routes for EVs such that all the shelter demands are fulfilled during their time windows and the total cost traveled by the fleet is minimized. To this end, we formulate the ESMDVRPTW as a mixed-integer linear programming model. Since the post-disaster transportation network contains a large number of vertices and arcs composed of vertices, we propose a two-stage approach to solve the ESMDVRPTW. The first stage is to obtain the minimal travel cost between any two vertices in real-time on a post-disaster transportation network using the proposed Floyd algorithm combined with the neighboring list (Floyd-NL algorithm). In the second stage, we develop the genetic algorithm (GA) incorporating large neighborhood search (GA-LNS), which determines the delivery scheme of shelters. Simulation results of the MDVRPTW benchmark illustrate that the performance of the GA-LNS is better than GA, simulated annealing (SA) and tabu search (TS). Finally, case studies are constructed on two real cases acquired from the OpenStreetMap (OSM) generated by the Quantum Geographic Information System (QGIS) in Ichihara city, Japan, and the test results of case studies show the effectiveness of the proposed two-stage approach. [ABSTRACT FROM AUTHOR]

Green and sustainable hydrogen has a major role in moving towards decarbonization of energy, providing viable solutions in all most challenging sectors of the national economies. It would penetrate practically all sectors of economic activity, such as long-haul transport, steel and chemical industries, power generation and energy storage. Green and sustainable hydrogen cost competitiveness is also closely linked to developments of large-scale renewable energy sources (in case of green hydrogen; hereinafter – RES) and further commercialization of carbon dioxide (in case of sustainable hydrogen produced from natural gas; hereinafter – CO2) capture and storage (hereinafter – CCS) technologies. In the European Union (hereinafter – EU), sustainable and especially green hydrogen is gaining strong political and business momentum, emerging as one of major components in governments' net zero plans within the European Green Deal and beyond. Being extremely versatile both in production and consumption sides, it is light, storable, has high energy content per unit mass and can be readily produced at an industrial scale. The key challenge comes from the fact that hydrogen is the lightest known chemical element and so has a low energy density per unit of volume, making some forms of long-distance transportation and storage complex and costly. In this paper, green and sustainable hydrogen is reviewed as a vital part of emerging European smart energy framework, which could contribute significantly to economy decarbonization agenda of the EU and Latvia in both in short- and mid-term perspective. [ABSTRACT FROM AUTHOR]