Small Hub Research Articles

Aircraft-Related Charges in European Airports: Determinants and Differentiation

Purpose: This study is focused on determination whether the size of an airport influences the airport's policy regarding the amount of aircraft-related airport charges. Additional test were conducted to determine whether airport charges are dependent on airport profile. Design/Methodology/Approach: The sample includes airports located in the European Union that in 2019 served more than 5 million passengers (threshold in accordance with the master EU-level Directive 2009/12/EC, 2009). The data records were also grouped into 3 sections representing large hubs, small- and medium-sized hubs and regional/LCC/charter airports. The airport charges data used for the analysis is supplied by own studies and calculation based on airports individual price lists for 2021. The research hypotheses were verified with the use of the classic regression model and Pearson Correlation Coefficient. Findings: The findings may indicate that larger airports leverage their market position and charge more for aircraft movements. However airports may also apply different policies, depending on whether they belong to small and medium-sized hubs or large ones. Practical Implications: Better understanding of airport pricing policies and their motivations may help: - Regulators – to better adjust the policy to the realities and needs of the market. - Airports – to ensure better and more effective approach airport charges. - Airlines – to better understand airport policy on airport charges and to enforce their positions on these charges more efficiently, including during their consultations. Originality/value: The existing research focuses on aeronautical revenue and airport charges in bulk. The proposed approach is more targeted and offers a more in-depth analysis of the nature of airport charges and their determinants at disaggregated level.

Case Study of Social Sustainability Practices in U.S. Small Hub Airports

Airports have economic, environmental, and social impacts on communities. Many of these impacts are influenced by airport management decisions. Airport sustainability may be thought of as having four primary areas: environmental, economic, operational, and social. The objective of this study is to understand better the adoption of social sustainability practices in small hub airport planning in the United States. The small hub airports in this study participated in the Federal Aviation Administration Airport Improvement Program for sustainability planning and have published their sustainability plans as either standalone sustainability management plans or integrated sustainable master plans. Plans from the six airports were gathered and examined as part of an exploratory case study analysis. The findings show that small hub airports do not use the same framework or select the same practices for social sustainability. Social sustainability practices for these six small hub airports focus on four stakeholder categories: passengers and travelers, employees, communities and local businesses, and concessionaires and tenants.

Widespread reorganisation of pluripotent factor binding and gene regulatory interactions between human pluripotent states

The transition from naive to primed pluripotency is accompanied by an extensive reorganisation of transcriptional and epigenetic programmes. However, the role of transcriptional enhancers and three-dimensional chromatin organisation in coordinating these developmental programmes remains incompletely understood. Here, we generate a high-resolution atlas of gene regulatory interactions, chromatin profiles and transcription factor occupancy in naive and primed human pluripotent stem cells, and develop a network-graph approach to examine the atlas at multiple spatial scales. We uncover highly connected promoter hubs that change substantially in interaction frequency and in transcriptional co-regulation between pluripotent states. Small hubs frequently merge to form larger networks in primed cells, often linked by newly-formed Polycomb-associated interactions. We identify widespread state-specific differences in enhancer activity and interactivity that correspond with an extensive reconfiguration of OCT4, SOX2 and NANOG binding and target gene expression. These findings provide multilayered insights into the chromatin-based gene regulatory control of human pluripotent states.

Investigation on the Alteration of Brain Functional Network and Its Role in the Identification of Mild Cognitive Impairment.

Mild cognitive impairment (MCI) is generally regarded as a prodromal stage of Alzheimer’s disease (AD). In coping with the challenges caused by AD, we analyzed resting-state functional magnetic resonance imaging data of 82 MCI subjects and 93 normal controls (NCs). The alteration of brain functional network in MCI was investigated on three scales, including global metrics, nodal characteristics, and modular properties. The results supported the existence of small worldness, hubs, and community structure in the brain functional networks of both groups. Compared with NCs, the network altered in MCI over all the three scales. In scale I, we found significantly decreased characteristic path length and increased global efficiency in MCI. Moreover, altered global network metrics were associated with cognitive level evaluated by neuropsychological assessments. In scale II, the nodal betweenness centrality of some global hubs, such as the right Crus II of cerebellar hemisphere (CERCRU2.R) and fusiform gyrus (FFG.R), changed significantly and associated with the severity and cognitive impairment in MCI. In scale III, although anatomically adjacent regions tended to be clustered into the same module regardless of group, discrepancies existed in the composition of modules in both groups, with a prominent separation of the cerebellum and a less localized organization of community structure in MCI compared with NC. Taking advantages of random forest approach, we achieved an accuracy of 91.4% to discriminate MCI patients from NCs by integrating cognitive assessments and network analysis. The importance of the used features fed into the classifier further validated the nodal characteristics of CERCRU2.R and FFG.R could be potential biomarkers in the identification of MCI. In conclusion, the present study demonstrated that the brain functional connectome data altered at the stage of MCI and could assist the automatic diagnosis of MCI patients.

Best practices in Internet of Things implementations at small commercial service airports

The internet of things (IoT) is transforming the passenger experience and operational efficiencies at commercial service airports. Strategies and tactics employed to implement IoT infrastructure have direct impacts on successful decision-making processes and risk mitigation, especially at small hub airports. This paper identifies best practices in IoT in the aviation industry over the past five years. Airport executives and information technology (IT) managers can benefit from this work to create business value within their organisation.

Business travel decisions and high-speed trains: an ordered logit approach

The paper studies the potential impact on business travel of the new high-speed railway line project, called AlpTransit, which will link Lugano, the small economic hub of the southern part of Switzerland, with Zurich, one of the major Swiss economic centres, situated north of the Alps. Thanks to this infrastructure, travel time between the two cities will decrease considerably from about three hours to less than two hours by the end of 2020.
 The question that we pose in this paper is what impact high-speed trains could have, in the short to medium term, on business travel between the two hubs (ex-ante evaluation). Indeed, given the travel time, firms could increase their business-to-business one-day trips, boosting face-to-face interactions within and among enterprises. Our curiosity more specifically regards the potential impact of the change in travel time on the propensity to travel of employees with different functions in various types of firms.
 An on-line survey was conducted among firms located in Ticino, the Swiss Canton that includes Lugano. The data are analysed using four ordered logit models, one for each employee category (CEO, administrative staff, sales personnel, specialists), since hierarchical position and professional status influence business travel characteristics. Results show that internal firm characteristics, such as sector, frequency and destination of current business travels significantly influence the propensity to travel to Zurich more often thanks to AlpTransit.

Collaborative Energy Efficiency for Modleach in WSN

Conceptual - Advancement in remote innovation described human life turn as basic and nice. Remote Ad hoc Sensor Network (WASN) is one of the benevolent remote systems used to screen the most horrible and consistently changing unique condition that limits constant human consideration. WASN has attracted huge consideration because of its unmistakable abilities to manage complex system activity in exceptionally asset compelled arrange build. WASN is turning into a demandable and advancing region of designing which has been right now occupied with different fields, especially to make remote correspondence framework successful and solid. WASN is settling continuous applications in the spots where geological, natural territories and climatic marvel are consistently fluctuating. This impromptu and unstructured arrangement of small sensor hubs work with controlled transmission run, preparing abilities, just as restricted battery reinforcement. Vitality is a crucial parameter in remote specially appointed sensor arrange. Especially, it has all the more dominant necessity under a powerful domain. The serious power exhaustion influences the presence of dynamic hubs. Consequently, information sending and solid parcel directing in such marvel situated system turning into a test. Grouping has made present remote sensor arrange framework vitality mindful because of information total, information combination and information pressure at bunch heads. That outcomes non repetitive message age and transmission, lead to least radio overhead. Yet, under completely powerful system condition the outcome isn't a lot of acceptable in Wireless Ad hoc Sensor Networks (WASNs).

Experimental Investigation of the Flow Mechanisms and the Performance Change of a Highly Loaded Axial Compressor Stage with/without Stator Hub Clearance

Three-dimensional corner separation is common in axial compressors, which can lead to large flow loss and blockage especially when it evolves into the corner stall (open separation). In this paper, the evolution of the three-dimensional flow structures inside a cantilevered stator of a 1.5 stage low-speed highly loaded axial compressor as the stator hub clearance varies, and its effect on the whole compressor performance are investigated experimentally. Firstly, when the stator hub is sealed, the hub corner stall will occur at small mass flow rate conditions. Then, when a very small stator hub clearance is introduced, the leakage flow tends to strengthen the hub corner separation at large mass flow rate conditions and prompts the occurrence of hub corner stall as the mass flow rate decreases. This is mainly caused by the fact that the leakage flow has relatively low energy due to the viscosity effect in the clearance and large flow loss generation as the clearance flow comes across and mixes with the transverse secondary flow. Finally, when the stator hub clearance increases, the effect of the flow viscosity becomes very weak and could be ignored, so the enhanced leakage flow can suppress the transverse migration of the low energy flow near the hub, and the hub corner separation at large mass flow rate conditions could be weakened and the hub corner stall at small mass flow rate conditions could be removed or delayed. As the stator hub clearance varies, the flow structures inside the stator passage could be summarized into five typical flow structures, and this is closely associated with the performance of the compressor.

Demonstration of a portable intracortical brain-computer interface

ABSTRACTWhile recent advances in intracortical brain-computer interfaces (iBCI) have demonstrated the ability to restore motor and communication functions, such demonstrations have generally been confined to controlled experimental settings and have required bulky laboratory hardware. Here, we developed and evaluated a self-contained portable iBCI that enabled the user to interact with various computer programs. The iBCI, which weighs 1.5 kg, consists of digital headstages, a small signal processing hub, and a tablet PC. A human participant tested the portable iBCI in laboratory and home settings under an FDA Investigational Device Exemption (NCT01894802). The participant successfully completed 96% of trials in a 2D cursor center-out task with the portable iBCI, a rate indistinguishable from that achieved with the standard laboratory iBCI. The participant also completed a variety of free-form tasks, including drawing, gaming, and typing.

The underwater survival of adult and larval stages of Argas persicus (Acari: Argasidae)

The soft tick, Argas persicus , is the most important ectoparasite in chicken and other domestic fowl, well as in humans. The main aim of this study was to evaluate the survival rate of A. persicus under three different environmental conditions, including immersion in tap water, immersion in oxygenated water and after being placed and washed along clothes in an ordinary washing machine. Adult and larval ticks were separately immersed in tap and oxygenated water for six different time periods: 1, 6, 24, 48, 72 hours and 1 week. Both adults and larvae survived up to 72 hours immersion in tap water. All the ticks immersed in tap water died during the first week; while 53.3% of adult ticks survived one week immersion in oxygenated water. To evaluate the survival rate of ticks in the washing machine, only adults were used and the ticks were placed in a small hub filter before being placed in a Samsung washing machine at three different temperatures (30, 40 and 60°C). At the end of each cycle, we counted the surviving ticks. All ticks survived 30 and 40 °C, while only 13.3% survived at 60 °C. In conclusion, adult and larval stages of A. persicus survived under water for couple of days while washing in regular washing machine did not kill adult ticks under temperatures of 30 and 40 °C. So in order to kill the ticks in clothes temperatures more than 60°C should be used.

110th Anniversary: Modeling National Power Flow Systems through the Energy Hub Approach

In this work, a large-scale modeling framework for the Mexican electricity system is developed based on the energy hub concept. The hub consists of nine smaller hubs, each one describing a control region of the country. The interface between energy carriers and loads is modeled as the product of coupling matrices. Natural gas, fuel oil, diesel, uranium, and coal were regarded as inputs, which are converted into electricity by available technologies. Power outputs are used mainly to meet the demand. We also considered hydroelectric, wind, and geothermal power contributions as well as export, import, and internal power transmission. A nonlinear programming problem was formulated and solved with real data for a 1 h scenario. Constraints on clean technologies’ participation and operation limits were taken into consideration. Results provide optimal flows and dispatch of the inputs such that an economic objective function is minimized while the demand of each region is satisfied. The combined cycle working with natural gas was the predominant process to produce electricity. Renewable sources played an important role in the fulfillment of the country’s energy demand. The nationwide energy hub developed in this work is a potential tool for planning and renewable resource integration studies.

Finding a Middle Way to Sustainable Food Systems

First paragraphs: The premise of Susan Futrell’s Good Apples: Behind Every Bite is that by understanding the environmental, social, and economic issues affect­ing apples growers in America, the reader can better appreciate and support sustainable food systems. Futrell’s storytelling is grounded in her years of experience working in sustainable food distribution, which includes 25 years in sales and marketing for a cooperatively owned natural food distributor called Blooming Prairie Warehouse in the Midwest, and her current work with Red Tomato, a small nonprofit food hub based in Massachusetts, where she helped develop the Eco Apple® program. From the beginning, Futrell resists the pressure to simplify and dichotomize complexities. Chapter 1, At the Intersection of Apples and Local, establishes this tone with her contextual consideration of how the term local is defined. Chapter 2, Immigrant Apples, reviews the history of apples in America. In it she discusses key historical figures and the emer­gence of seedling nurseries, apple varieties, grow­ers’ associations, and land-grant institutions. . . .

Exploring the benefits of vertically staggered wind farms: Understanding the power generation mechanisms of turbines operating at different scales

AbstractWind farms are known to modulate large scale structures in and around the wake regions of the turbines. The potential benefits of placing small hub height, small rotor turbines in between the large turbines in a wind farm to take advantage of such modulated large‐scale eddies are explored using large eddy simulation (LES). The study has been carried out in an infinite wind farm framework invoking an asymptotic limit, and the wind turbines are modeled using an actuator line model. The vertically staggered wind turbine arrangements that are studied in the present work consist of rows of large wind turbines, with rows of smaller wind turbines (ie, smaller rotor size and shorter hub height) placed in between the rows of large turbines. The influence of the hub height of the small turbines, in particular, how it affects the interactions between the large and small turbines and consequently their power, along with the multiscale dynamics involved, has been assessed in the current study. It was found that, in the multiscale layouts, the small turbines at lower hub heights operate more efficiently than their homogeneous single‐scale counterparts. In contrast, the small turbines with higher hub heights incur a loss of power compared with the corresponding single‐scale arrangements.

Preliminary design of the internal geometry in a minimally invasive left ventricular assist device under pulsatile-flow conditions.

A minimally invasive, partial-assist, intra-atrial blood pump has been proposed, which would unload the left ventricle with a flow path from the left atrium to the arterial system. Flow modulation is a common strategy for ensuring washout in the pump, but it can increase power consumption because it is typically achieved through motor-speed variation. However, if a pump's performance curve had the proper gradient, flow modulation could be realized passively. To achieve this goal, we propose a pump performance operating curve as an alternative to the more standard operating point. Mean-line theory was employed to generate an initial set of geometries that were then tested on a hydraulic test rig at ~20,000 r/min. Experimental results show that the intra-atrial blood pump performed below the operating region; however, it was determined that smaller hub diameter and longer chord length bring the performance of the intra-atrial blood pump device closer to the operating curve. We found that it is possible to shape the pump performance curve for specifically targeted gradients over the operating region through geometric variations inside the pump.

Using behavioral and neural measures to assess training in scene categorization

Using behavioral and neural measures to assess training in scene categorization

How Free Trade Agreements Affect Exports and Imports in Vietnam

The important year of 1995 marked Vietnam’s first integration as a member of ASEAN. By 2016, Vietnam had negotiated, signed, and implemented sixteen free trade agreements. They include both multilateral and bilateral free trade agreements such as the China-ASEAN, Vietnam-Chile, and Vietnam-Japan agreements. By signing free trade agreements Vietnam can increase trade flows in bilateral and multilateral developed-country FTA scenarios. Trade creation and diversion can be found in multilateral developing-country FTA scenarios and the author finds the impacts of each free trade agreement is different if analyzed for each 2-digit commodity.
 Keywords
 Free trade agreement, trade, import, export.t commodity
 References
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Assessing Land Use-Cover Changes and Modelling Change Scenarios in Two Mountain Spanish National Parks

Land Use-Cover Changes (LUCCs) are one of the main problems for the preservation of biodiversity. Protected Areas (PAs) do not escape this threat. Some processes, such as intensive recreational use, forest fires or the expansion of artificial areas taking place inside and around them in response to their appeal, question their environmental sustainability and their efficiency. In this paper, we analyze the LUCCs that took place between 1990 and 2006 in two National Parks (NPs) belonging to the Spanish network and in their surroundings: Ordesa and Monte Perdido (Ordesa NP) and Sierra de Guadarrama (Guadarrama NP). We also simulate land use changes between 2006 and 2030 by means of Artificial Neural Networks (ANNs), taking into account two scenarios: trend and green. Finally, we perform a multi-temporal analysis of natural habitat fragmentation in each NP. The results show that the NPs analyzed are well-preserved and have seen hardly any significant LUCCs inside them. However, Socioeconomic Influence Zones (SIZs) and buffers are subject to different dynamics. In the SIZ and buffer of the Ordesa NP, there has been an expansion of built-up areas (annual rate of change = +1.19) around small urban hubs and ski resorts. There has also been a gradual recovery of natural areas, which had been interrupted by forest fires. The invasion of sub-alpine grasslands by shrubs is clear (+2735 ha). The SIZ and buffer of the Guadarrama NP are subject to urban sprawl in forest areas and to the construction of road infrastructures (+5549 ha and an annual rate of change = +1.20). Industrial area has multiplied by 3.3 in 20 years. The consequences are an increase in the Wildland-Urban Interface (WUI), greater risk of forest fires and greater fragmentation of natural habitats (+0.04 in SIZ). In the change scenarios, if conditions change as expected, the specific threats facing each NP can be expected to increase. There are substantial differences between the scenarios depending on whether or not incentives are accepted and legal restrictions are respected.

‘Knowledge leech’ to ‘part of the team’: students’ learning in rural communities of practice

Background: Keele Medical School has a small accommodation hub for students placed within ten associated general practices in a predominantly rural area of England. Groups of up to eleven final year students spend fifteen weeks learning generic and transferable clinical skills in these practices.Aim: To explore the evolving perceptions on students on their experiences throughout their placements.Method: All ten students placed at the hub between August and December 2013 were invited to participate in focus groups in weeks zero, seven, and fifteen. Analysis was qualitative and thematic.Results: Ten, five and eight students chose to participate in successive focus groups. Five themes were identified from the data; acceptance, learning opportunities, relationships, development, and injustice with a subtheme of isolation.Conclusion: The placements had a powerful impact on students’ learning and development. Their perceptions changed from seeing themselves as ‘knowledge leeches’ to legitimate contributors to health care over the course of fifteen weeks. They did not recognise that managing perceived adversity led to personal development. This illustrates the need to both identify perceived adversity and explicitly signpost and scaffold life learning. The students described experiences which challenged them intellectually and offered them opportunities to recognise the breadth and complexity of general practice.

Demand side management scheme in smart grid with cloud computing approach using stochastic dynamic programming

Summary This paper proposes a cloud computing framework in smart grid environment by creating small integrated energy hub supporting real time computing for handling huge storage of data. A stochastic programming approach model is developed with cloud computing scheme for effective demand side management (DSM) in smart grid. Simulation results are obtained using GUI interface and Gurobi optimizer in Matlab in order to reduce the electricity demand by creating energy networks in a smart hub approach.

On the Complexity of Life Cycle Inventory Networks: Role of Life Cycle Processes with Network Analysis

SummaryDetermining the relevance and importance of a technosphere process or a cluster of processes in relation to the rest of the industrial network can provide insights into the sustainability of supply chains: those that need to be optimized or controlled/safeguarded. Network analysis (NA) can offer a broad framework of indicators to tackle this problem. In this article, we present a detailed analysis of a life cycle inventory (LCI) model from an NA perspective. Specifically, the network is represented as a directed graph and the “emergy” numeraire is used as the weight associated with the arcs of the network. The case study of a technological system for drinking water production is presented. We investigate the topological and structural characteristics of the network representation of this system and compare properties of its weighted and unweighted network, as well as the importance of nodes (i.e., life cycle unit processes). By identifying a number of advantages and limitations linked to the modeling complexity of such emergy‐LCI networks, we classify the LCI technosphere network of our case study as a complex network belonging to the scale‐free network family. The salient feature of this network family is represented by the presence of “hubs”: nodes that connect with many other nodes. Hub failures may imply relevant changes, decreases, or even breaks in the connectedness with other smaller hubs and nodes of the network. Hence, by identifying node centralities, we can rank and interpret the relevance of each node for its special role in the life cycle network.