Optimal pitching schedules for a cycloidal rotor in hovering

2016 ◽  
Vol 88 (5) ◽  
pp. 623-635
Author(s):  
Andrea Andrisani ◽  
Diego Angeli ◽  
Antonio Dumas
Keyword(s):  
Power Efficiency ◽  
Geometrical Parameters ◽  
Mean Power ◽  
Content Type ◽  
Computational Fluid Dynamics Cfd ◽  
The Mean ◽  
Sinusoidal Functions ◽  
Definition Of ◽  
Propulsion Concept ◽  
Practical Implications

Purpose The purpose of this paper is to define an optimal pitching profile for the blades of a cycloidal rotor which minimizes the mean power consumption for a given mean thrust of the rotor. Design/methodology/approach A simple analytical model of the kinematics and aerodynamics of a cycloidal rotor is defined first to obtain expressions for thrust and power depending on the pitching profile and geometrical parameters of the rotor. Then, Lagrange optimization is applied to obtain the optimal pitching schedule under hovering conditions. Finally, results of the theoretical analysis are compared with those of a two-dimensional computational fluid dynamics (CFD) model. Findings Results of the optimization suggest that the optimal profile is a combination of sinusoidal functions. It is shown that the adoption of the optimal pitching schedule could improve the power efficiency of the rotor by approximately 25 per cent. Practical implications The possibility to increase the efficiency of a cycloidal rotor by acting on its pitching schedule could be a significant factor of success for this alternative propulsion concept. Originality/value The present work represents the first attempt at a definition of an optimal pitching profile for a cycloidal rotor. Moreover, although being carried out on the basis of simplified analytical considerations, the present investigation sets a methodological framework which could be successfully applied to the design of similar kinds of systems.

Interaction, engagement, and perceived interactivity in single-handed interaction

2016 ◽  
Vol 26 (5) ◽  
pp. 1134-1157 ◽  
Author(s):  
Donghee Shin ◽  
Myunggoon Choi ◽  
Jang Hyun Kim ◽  
Jae-gil Lee
Keyword(s):  
Behavioral Intention ◽  
Interaction Techniques ◽  
Content Type ◽  
Thumb Movement ◽  
Wide Range ◽  
Mobile Industry ◽  
Perceived Interactivity ◽  
The Subject ◽  
Definition Of ◽  
Practical Implications

Purpose The purpose of this paper is to examine the effects of interaction techniques (e.g. swiping and tapping) and the range of thumb movement on interactivity, engagement, attitude, and behavioral intention in single-handed interaction with smartphones. Design/methodology/approach A 2×2 between-participant experiment (technological features: swiping and tapping×range of thumb movement: wide and narrow) was conducted to study the effects of interaction techniques and thumb movement ranges. Findings The results showed that the range of thumb movement had significant effects on perceived interactivity, engagement, attitude, and behavioral intention, whereas no effects were observed for interaction techniques. A narrow range of thumb movement had more influence on the interactivity outcomes in comparison to a wide range of thumb movement. Practical implications While the subject of actual and perceived interactivity has been discussed, the issue has not been applied to smartphone. Based on the research results, the mobile industry may come up with a design strategy that balances feature- and perception-based interactivity. Originality/value This study adopted the perspective of the hybrid definition of interactivity, which includes both actual and perceived interactivity. Interactivity effect outcomes mediated by perceived interactivity.

The operational efficiency of passenger aircraft

2006 ◽  
Vol 78 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Donald McLean
Keyword(s):  
Design Methodology ◽  
Operational Efficiency ◽  
Civil Aviation ◽  
Content Type ◽  
Transport Economics ◽  
Load Factors ◽  
Consistent Assessment ◽  
Definition Of ◽  
Passenger Aircraft ◽  
Practical Implications

PurposeTo provide for the use of airlines and other civil aviation organizations a practical definition of operational efficiency and to show how it can be determined.Design/methodology/approachA brief account of air transport economics is used to demonstrate how bom load factors and aircraft utilization need to be considered in assessing operational efficiency. Then other efficiencies are treated briefly before an example is given of how the better of two fictitious aircraft can be chosen for a particular route. A second example involving the calculation of the operational efficiency achieved by an imaginary airline is also given to show that the typical value is lower than might be expected, particularly in view of the relatively high load factors involved.FindingsProvides performance values and economic figures which are typical of current airline operations.Practical implicationsUse of the proposed definition will allow the consistent assessment of the economic performance of airlines.Originality/valueAt present there is no definition of operational efficiency in general use although it is greatly needed by airlines. The definition proposed in this paper is practical and easy to use.

Digital competences of the workforce – a research topic?

2017 ◽  
Vol 23 (3) ◽  
pp. 721-734 ◽  
Author(s):  
Matthias Murawski ◽  
Markus Bick
Keyword(s):  
Research Topic ◽  
Future Research ◽  
Digital Competence ◽  
Content Type ◽  
Research Activities ◽  
Starting Point ◽  
Pros And Cons ◽  
Definition Of ◽  
The Individual ◽  
Practical Implications

Purpose Considering working in the digital age, questions on the consequences for the individual workers are, so far, often neglected. The purpose of this paper is to deal with the question of whether the digital competences of the workforce is a research topic. The authors argue for the thesis that it is indeed a research topic. Design/methodology/approach In addition to a literature analysis of the top IS, HR, and learning publications, non-scientific sources, as well as the opinions of the authors, are included. The authors’ thesis is challenged through a debate of corresponding pros and cons. Findings The definition of digital competences lacks scientific depth. Focussing on the workforce is valid, as a “lifelong” perspective is not mandatory for research. Digital competence research is a multidisciplinary task to which the IS field can make a valuable contribution. Research limitations/implications Although relevant references are included, some aspects are mainly driven by the opinions of the authors. The theoretical implications encompass a call for a scientific definition of digital competences. Furthermore, scholars should focus on the competences of the workforce, including occupations, roles, or industries. The authors conclude by providing a first proposal of a research agenda. Practical implications The practical implications include the alignment of multiple stakeholders for the design of “digital” curricula and the integration by HR departments of the construct of digital competences, e.g. for compensation matters and job requirements. Originality/value This paper is one of very few contributions in the area of the digital competences of the workforce, and it presents a starting point for future research activities.

scholarly journals Time required to move cash through slot machines

2018 ◽  
Vol 21 (3) ◽  
pp. 376-384 ◽  
Author(s):  
Karen Kelly ◽  
Carl James Schwarz ◽  
Ricardo Gomez ◽  
Kim Marsh
Keyword(s):  
British Columbia ◽  
Slot Machines ◽  
Content Type ◽  
The Public ◽  
Average Value ◽  
The Mean ◽  
Time Required ◽  
Rest Breaks ◽  
Mean Time ◽  
Practical Implications

Purpose The purpose of this paper is to present an empirical study on the time needed to load and disburse cash using bill validators on slot machines and stand-alone cash dispensers in casinos in British Columbia under a Ticket In Ticket Out (TITO) system. Design/methodology/approach Testing took place over two days, using 18 machines. The results were extrapolated to estimate the approximate time required to process $1,000,000 with different average bill amounts in the cash mix and three different bill validator machines in common use. The average value per bill using the cash mix used by the public in the casino was $33.11 [standard error (SE) $2.11]. Findings The mean time/accepted note ranged from 4.12 to 9.65 s, depending on bill validator type. This implies that the time needed to load $1,000,000 onto credit slips using bill validators on slot machines ranges from 35 to 81 h, excluding rest breaks and other breaks. The time needed to redeem $1,000,000 is estimated to be 3 h. Practical/implications The implications of these finding for illicit actors to successfully launder large amounts of cash are discussed. Given the time needed to physically handle the cash, and other control systems currently in use in casinos in British Columbia, processing large amounts of cash using bill validators on slot machines would require a highly organized team that would find it difficult to elude detection. Originality/value The trial results provide a baseline estimate to be used going forward when investigating or proposing money laundering methodologies that include slot machines.

Numerical evaluation of separation efficiency in the diverging T-junction for slug flow

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Faheem Ejaz ◽  
William Pao ◽  
Hafiz Muhammad Ali
Keyword(s):  
Slug Flow ◽  
Design Methodology ◽  
Separation Efficiency ◽  
Fluid Model ◽  
Diameter Ratio ◽  
Maintenance Costs ◽  
Content Type ◽  
Computational Fluid Dynamics Cfd ◽  
Practical Implications ◽  
High Separation

Purpose Offshore industries encounter severe production downtime due to high liquid carryovers in the T-junction. The diameter ratio and flow regime can significantly affect the excess liquid carryovers. Unfortunately, regular and reduce T-junctions have low separation efficiencies. Ansys as a commercial computational fluid dynamics (CFD) software was used to model and numerically inspect a novel diverging T-junction design. The purpose of diverging T-junction is to merge the specific characteristics of regular and reduced T-junctions, ultimately increasing separation efficiency. The purpose of this study is to numerically compute the separation efficiency for five distinct diverging T-junctions for eight different velocity ratios. The results were compared to regular and converging T-junctions. Design/methodology/approach Air-water slug flow was simulated with the help of the volume of the fluid model, coupled with the K-epsilon turbulence model to track liquid-gas interfaces. Findings The results of this study indicated that T-junctions with upstream and downstream diameter ratio combinations of 0.8–1 and 0.5–1 achieved separation efficiency of 96% and 94.5%, respectively. These two diverging T-junctions had significantly higher separation efficiencies when compared to regular and converging T-junctions. Results also revealed that over-reduction of upstream and downstream diameter ratios below 0.5 and 1, respectively, lead to declination in separation efficiency. Research limitations/implications The present study is constrained for air and water as working fluids. Nevertheless, the results apply to other applications as well. Practical implications The proposed T-junction is intended to reduce excessive liquid carryovers and frequent plant shutdowns. Thus, lowering operational costs and enhancing separation efficiency. Social implications Higher separation efficiency achieved by using diverging T-junction enabled reduced production downtimes and resulted in lower maintenance costs. Originality/value A novel T-junction design was proposed in this study with a separation efficiency of higher than 90%. High separation efficiency eliminates loss of time during shutdowns and lowers maintenance costs. Furthermore, limitations of this study were also addressed as the lower upstream and downstream diameter ratio does not always enhance separation efficiency.

The pathway to marketplace insight: structuring the analysis context

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Liam Fahey
Keyword(s):  
Decision Making ◽  
Design Methodology ◽  
Content Type ◽  
Critical Part ◽  
Early Stages ◽  
Working Definition ◽  
Marketing Analysis ◽  
Definition Of ◽  
Practical Implications

Purpose By clearly mapping the pathway for managing the early stages of any marketplace analysis project, its definition, scope, framing, focus, perspective, context, imagination and data choices – the odds of generating important strategic insight can be greatly increased for executives as well as analysis teams. Design/methodology/approach A marketing analysis team should pay specific attention to how it organizes the analysis context’a process called “Structuring”. Findings A working definition of insight: new marketplace understanding that makes a difference to the organization’s thinking, decision making and action. Practical/implications 10; Nothing constricts the insight structuring process as much as lack of imagination! Originality/value The choice of analysis scope, framing, focus, perspective or methods is a critical part of the marketplace analysis structuring process that increases the possibility of distinctly different strategic inferences emerging. The article is a much needed guide to mastering strategic insight for executives and marketplace analysts.

Composition of Indian microfinance: a case for competing logics

2019 ◽  
Vol 27 (5) ◽  
pp. 1298-1316
Author(s):  
Sushanta Kumar Sarma
Keyword(s):  
Design Methodology ◽  
Belief System ◽  
Hybrid Organizations ◽  
Identity Conflict ◽  
Organizational Field ◽  
Social Entrepreneurs ◽  
Content Type ◽  
Institutional Infrastructure ◽  
Definition Of ◽  
Practical Implications

Purpose This paper aims to understand how competing logics can co-exist in the organizational field of Indian microfinance. Design/methodology/approach The paper uses the theoretical lens of an organizational field to understand the composition of the microfinance field. Using the definition of an organizational field, key players in Indian microfinance are identified and their interactions within the field are analysed to understand the emergence and co-existence of multiple logics. The data used for this paper are collected from published work on Indian microfinance. Findings The co-existence of competing logics is sustained through the creation of two sub-fields within Indian microfinance. Each of the sub-field is dominated by one institutional logic. The field originated in developmental logic of microfinance and gradually adopted the banking logic post-2000. The sub-fields are dominated by different organizational forms with different nature of interaction within the field. Research limitations/implications Actors within the field would experience institutional complexity with lesser intensity because of the existence of two distinct sub-communities with individual logic. Dual logics can sustain itself independently provided these are embedded in two different sub-communities. Despite the emergence of a new logic, the previous logic can still remain relevant given the enabling support from institutional infrastructure. Practical implications The manifestation of development and banking logics through practices and the belief system in Indian microfinance would offer useful insights for social entrepreneurs balancing the dual goals of hybrid organizations. Due to the sub-communities, a professional working with different forms of organization would experience little pressure to adjust to diverse logic and would also experience no or little identity conflict. Originality/value This paper focuses on the microfinance sector in India as an organizational field and explores the mechanism of co-existence of the dual goals of microfinance at the field level.

scholarly journals Building an integrated enhanced virtual research environment metadata catalogue

2019 ◽  
Vol 37 (6) ◽  
pp. 929-951 ◽  
Author(s):  
Laurent Remy ◽  
Dragan Ivanović ◽  
Maria Theodoridou ◽  
Athina Kritsotaki ◽  
Paul Martin ◽  
...  
Keyword(s):  
Data Model ◽  
Data Science ◽  
Science Research ◽  
Dublin Core ◽  
Content Type ◽  
Knowledge Based ◽  
Novel Approach ◽  
Virtual Research Environment ◽  
Definition Of ◽  
Practical Implications

Purpose The purpose of this paper is to boost multidisciplinary research by the building of an integrated catalogue or research assets metadata. Such an integrated catalogue should enable researchers to solve problems or analyse phenomena that require a view across several scientific domains. Design/methodology/approach There are two main approaches for integrating metadata catalogues provided by different e-science research infrastructures (e-RIs): centralised and distributed. The authors decided to implement a central metadata catalogue that describes, provides access to and records actions on the assets of a number of e-RIs participating in the system. The authors chose the CERIF data model for description of assets available via the integrated catalogue. Analysis of popular metadata formats used in e-RIs has been conducted, and mappings between popular formats and the CERIF data model have been defined using an XML-based tool for description and automatic execution of mappings. Findings An integrated catalogue of research assets metadata has been created. Metadata from e-RIs supporting Dublin Core, ISO 19139, DCAT-AP, EPOS-DCAT-AP, OIL-E and CKAN formats can be integrated into the catalogue. Metadata are stored in CERIF RDF in the integrated catalogue. A web portal for searching this catalogue has been implemented. Research limitations/implications Only five formats are supported at this moment. However, description of mappings between other source formats and the target CERIF format can be defined in the future using the 3M tool, an XML-based tool for describing X3ML mappings that can then be automatically executed on XML metadata records. The approach and best practices described in this paper can thus be applied in future mappings between other metadata formats. Practical implications The integrated catalogue is a part of the eVRE prototype, which is a result of the VRE4EIC H2020 project. Social implications The integrated catalogue should boost the performance of multi-disciplinary research; thus it has the potential to enhance the practice of data science and so contribute to an increasingly knowledge-based society. Originality/value A novel approach for creation of the integrated catalogue has been defined and implemented. The approach includes definition of mappings between various formats. Defined mappings are effective and shareable.

Fostering digital transformation of SMEs: a four levels approach

2020 ◽  
Vol 58 (8) ◽  
pp. 1543-1562 ◽  
Author(s):  
Antonello Garzoni ◽  
Ivano De Turi ◽  
Giustina Secundo ◽  
Pasquale Del Vecchio
Keyword(s):  
Digital Technologies ◽  
Digital Transformation ◽  
Temporal Dimension ◽  
Content Type ◽  
South Italy ◽  
Apulia Region ◽  
Relevant Variables ◽  
Four Levels ◽  
Definition Of ◽  
Practical Implications

PurposeThe purpose of this paper is to analyse how digital technologies trigger changes in the business process of manufacturing small and medium-sized enterprises (SMEs) in the Apulia Region (South Italy). As SMEs play an essential role in the process value creation of industries and countries, the article examines the enablers of Industry 4.0 in a regional contexts characterized by delay in research and development and innovation performances where the companies' competitiveness is based on limited knowledge and technological assets.Design/methodology/approachThe case study of Smart District 4.0, an ongoing project aimed to promote the digitalization of SMEs operating in the Agri–Food, Clothing–Footwear and Mechanics–Mechatronics in the Apulia Region (South Italy) is analysed. The project has been financed by the Italian Ministry of Economic Development with the final aim to sustain the digital transformation of SMEs in South Italy.FindingsThe results introduce a four levels approach of engagement of SMEs in the adoption of digital technologies, namely, digital awareness, digital enquirement, digital collaboration and digital transformation. Furthermore, for each level of engagement the study describes and discusses some relevant variables that could be used by managers and entrepreneurs to assess the level of readiness for utilization of digital technologies and how to digitalize some processes.Practical implicationsPractical implications regard the definition of a roadmap useful to assess and manage the level of digital transformation of SMEs. Limitations of the study regarding the temporal dimension of the evidences associated to the Smart District 4.0 as well as to the regional context was analysed.Originality/valueOriginality resides in the definition of a roadmap for the digital transformation of SMEs in a region where the profile of companies' digital maturity is still low.

The simulation of single wraparound fin on a semi-cylindrical missile body

2020 ◽  
Vol 92 (3) ◽  
pp. 418-427 ◽  
Author(s):  
Nayhel Sharma ◽  
Rakesh Kumar
Keyword(s):  
Research Study ◽  
Cfd Simulation ◽  
Three Dimensional ◽  
Future Research ◽  
Aerodynamic Coefficients ◽  
Content Type ◽  
Computational Fluid Dynamics Cfd ◽  
Predicted Values ◽  
Characteristic Trend ◽  
Practical Implications

Purpose The purpose of this paper is to establish a freestream computational fluid dynamics (CFD) model of a three-dimensional non-spinning semi-cylindrical missile model with a single wrap around fin in Mach 2.70-3.00M range and 0° angle of attack, and ultimately establishing itself for future research study. Design/methodology/approach In this study, the behaviour of flow around the fin was investigated using a κ-ϵ turbulence model of second-order of discretization. This was done using a highly structured mesh. Additionally, an inviscid CFD simulation involving the same boundary conditions have also been carried out for comparison. Findings The obtained values of aerodynamic coefficients and pressure contours visualizations are compared against their experimental and computational counterparts. A typical missile aerodynamic characteristic trend can be seen in the current CFD. Practical implications The predicted values of the aerodynamic coefficients of this single fin model have also been compared to those of the full missile body comprising of four fins from the previous research studies, and a similar aerodynamic trend can be seen. Originality/value This study explores the possibility of the use of turbulence modelling in a single fin model of a missile and provides a basic computational model for further understanding the flow behaviour near the fin.

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