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Article
Publication date: 7 March 2016

Frank Holzäpfel, Anton Stephan, Tobias Heel and Stephan Körner

From pilot reports, field measurements and numerical simulations, it is known that wake vortices may persist within the glide path in ground proximity, leading to an…

Abstract

Purpose

From pilot reports, field measurements and numerical simulations, it is known that wake vortices may persist within the glide path in ground proximity, leading to an increased encounter risk. This paper aims to investigate wake vortex behaviour during final approach and landing to understand why landings can be safe nevertheless. Further, it is investigated whether and to which extent the installation of plate lines beyond the runway tails may further accelerate wake vortex decay and thus improve safety by reducing the number of wake vortex encounters.

Design/methodology/approach

A hybrid numerical simulation approach is used to investigate vortex evolution from roll-up until final decay during the landing manoeuvre. The simulations are complemented by field measurement data accomplished at Munich Airport and at Special Airport Oberpfaffenhofen.

Findings

During touchdown, the so-called end effects trigger pressure disturbances and helical vortex structures that appear to ensure vortex decay rates in ground proximity needed to guarantee the required safety targets of aviation. Light detection and ranging (LIDAR) measurements indicate that vortex decay indeed can be accelerated by a plate line installed on the ground surface. The lifetime of the most safety relevant, long-lived and strongest vortices can be reduced by one-third.

Practical implications

The installation of plate lines beyond the runway tails may improve safety by reducing the number of wake vortex encounters and increase the efficiency of wake vortex advisory systems.

Originality/value

The novel numerical simulation technique and the acquired insights into the wake vortex phenomena occurring during landing as well as the demonstration of the functionality of the patented plate line provide high originality and value for both science and operational application.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 88 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 15 March 2018

Sascha Kraus, Patrycja Klimas, Johanna Gast and Tobias Stephan

The purpose of this paper is to highlight the specific types of coopetition between small and medium-sized craft breweries and related businesses, as well as its drivers…

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Abstract

Purpose

The purpose of this paper is to highlight the specific types of coopetition between small and medium-sized craft breweries and related businesses, as well as its drivers and outcomes.

Design/methodology/approach

Qualitative research was carried out using in-depth, semi-structured interviews with 18 different small and medium-sized enterprises (SMEs) combined with site visits and secondary data analysis.

Findings

The results reveal that craft breweries are engaging in coopetition in several different ways. Mutual benefit, trust, commitment, and sympathy are the crucial drivers for coopetition; whereas innovation development, market reach and marketing, as well as firm growth represent the key shared outcomes of coopetition.

Research limitations/implications

This study suffers from two main limitations, including the focus on coopetition of craft breweries operating in German-speaking countries only and the risk of subjectivity in analysis and interpretation due to the qualitative, explorative nature of the research.

Originality/value

The findings reveal insights into the uniqueness of SMEs – specifically craft brewers – regarding coopetition, which is currently of strong cooperative nature. This study completes prior coopetition knowledge by revealing the importance of coopetition for small, micro and resource-constrained firms operating in dynamic and innovative but traditional (here craft) industries; presenting the cooperation-based type of coopetition as a good competition strategy under fierce competition from large, more established and global business rivals; and identifying sympathy as an important coopetition driver.

Details

International Journal of Entrepreneurial Behavior & Research, vol. 25 no. 1
Type: Research Article
ISSN: 1355-2554

Keywords

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Article
Publication date: 7 March 2016

Stephan Körner and Frank Holzäpfel

Wake vortices that are generated by an aircraft as a consequence of lift constitute a potential danger to the following aircraft. To predict and avoid dangerous…

Abstract

Purpose

Wake vortices that are generated by an aircraft as a consequence of lift constitute a potential danger to the following aircraft. To predict and avoid dangerous situations, wake vortex transport and decay models have been developed. Being based on different model physics, they can complement each other with their individual strengths. This paper investigates the skill of a Multi-Model Ensemble (MME) approach to improve prediction performance. Therefore, this paper aims to use wake vortex models developed by NASA (APA3.2, APA3.4, TDP2.1) and by DLR (P2P). Furthermore, this paper analyzes the possibility to use the ensemble spread to compute uncertainty envelopes.

Design/methodology/approach

An MME approach called Reliability Ensemble Averaging (REA) is adapted and used to the wake vortex predictions. To train the ensemble, a set of wake vortex measurements accomplished at the airports of Frankfurt (WakeFRA), Munich (WakeMUC) and at a special airport Oberpfaffenhofen was applied.

Findings

The REA approach can outperform the best member of the ensemble, on average, regarding the root-mean-square error. Moreover, the ensemble delivers reasonable uncertainty envelopes.

Practical implications

Reliable wake vortex predictions may be applicable for both tactical optimization of aircraft separation at airports and airborne wake vortex prediction and avoidance.

Originality/value

Ensemble approaches are widely used in weather forecasting, but they have never been applied to wake vortex predictions. Until today, the uncertainty envelopes for wake vortex forecasts have been computed among others from perturbed initial conditions or perturbed physics as well as from uncertainties from environmental conditions or from safety margins but not from the spread of structurally independent model forecasts.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 88 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 18 April 2017

Stephan Winterhalter, Tobias Weiblen, Christoph H. Wecht and Oliver Gassmann

Despite the fact that business model innovation (BMI) has attracted intense attention from scholars and practitioners alike, practicable knowledge on the organizational…

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Abstract

Purpose

Despite the fact that business model innovation (BMI) has attracted intense attention from scholars and practitioners alike, practicable knowledge on the organizational implementation of BMI efforts in large multinational corporations is rather rare. This paper aims to investigate how BMI is managed in the complex environment of the chemical industry based on a study at BASF SE, a leading global chemical company.

Design/methodology/approach

The empirical data draw from six case studies (i.e. six BMI projects) within BASF which were observed in the 2010-2014 timeframe.

Findings

There is not one uniform BMI process archetype. Three different types can be identified, whereby the degree of technology involvement and the maturity of this technology act as determining factors for the form of the process and its organizational implementation.

Originality/value

This paper profits from its unique empirical setting, which allows identifying practices for the organizational implementation of systematic BMI processes in large corporations. The guidelines derived are highly relevant for general managers and business development departments.

Details

Journal of Business Strategy, vol. 38 no. 2
Type: Research Article
ISSN: 0275-6668

Keywords

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Book part
Publication date: 31 July 2014

Aaron F. McKenny

This chapter provides an article-by-article annotated bibliography of the extant social entrepreneurship literature from the top management and entrepreneurship journals…

Abstract

Purpose

This chapter provides an article-by-article annotated bibliography of the extant social entrepreneurship literature from the top management and entrepreneurship journals. Special emphasis is given to the methods used in empirical studies, providing a one-stop reference to scholars interested in conducting social entrepreneurship research.

Methodology/Approach

Forty-three social entrepreneurship articles from ten top management and entrepreneurship journals were selected and summarized.

Details

Social Entrepreneurship and Research Methods
Type: Book
ISBN: 978-1-78441-141-1

Keywords

Abstract

The “New Economy” was the economic buzzword of the 1990s. Digitization and networking, accompanied disproportionally by an increasing efficiency of information and communication technology exchanges, served as the foundation for sustainable economic changes in the way business is conducted (Gersch & Goeke, 2004). The new Internet architecture and the economic transactions that are based on it became of increasing importance worldwide.

Details

New Technology-Based Firms in the New Millennium
Type: Book
ISBN: 978-0-0805-5448-8

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Article
Publication date: 5 June 2017

Tobias Ebbing and Marzenna Cichosz

The purpose of this paper is to contribute to the discussion of transferring modern technology from industries such as logistics to the life of elderly in a way that they…

Abstract

Purpose

The purpose of this paper is to contribute to the discussion of transferring modern technology from industries such as logistics to the life of elderly in a way that they can understand, accept and make use of it.

Design/methodology/approach

This is a conceptual discussion based on findings from a series of projects in healthcare, IT development and consultancy. The key methodologies considered include technology assessment, scenario development, listening to people with dementia and their caregivers and non-participant observation, as well as reviews of good practice, policy and literature.

Findings

The transfer considerations showed unreasonable price differences of similar hardware used for localization between the logistics and the elderly market. Bluetooth low energy (BLE) was identified as a promising localization technique. A gap in the marketing of technology for the elderly was identified, virtually fencing the elderly market.

Practical implications

A lack of transparency fosters market skimming, resulting in deadweight loss for society and technology being restrained from less-solvent consumers. Corrective actions like entrepreneurship facilitation and consumer education should be considered to overcome this market failure. To persevere in a consequently more competitive market, changes in marketing should be considered.

Originality/value

The work assesses the presence of the innovativeness–needs paradox of Everett Rogers in the field of innovation for the elderly on the basis of an example and identifies the resulting market failure. It suggests a market-entry mode and briefly lays out the marketing modes for market penetration.

Details

International Journal of Pharmaceutical and Healthcare Marketing, vol. 11 no. 2
Type: Research Article
ISSN: 1750-6123

Keywords

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Article
Publication date: 19 January 2021

Andreas Schwarz, Martin Ebner, Thomas Lohner, Karsten Stahl, Kirsten Bobzin, Tobias Brögelmann, Christian Kalscheuer and Matthias Thiex

This paper aims to address the influence of diamond-like carbon (DLC) coatings on the frictional power loss of spur gears. It shows potentials for friction and bulk…

Abstract

Purpose

This paper aims to address the influence of diamond-like carbon (DLC) coatings on the frictional power loss of spur gears. It shows potentials for friction and bulk temperature reduction in industrial use. From a scientific point of view, the thermal insulation effect on fluid friction is addressed, which lowers viscosity in the gear contact due to increasing contact temperature.

Design/methodology/approach

Thermal insulation effect is analyzed in detail by means of the heat balance and micro thermal network of thermal elastohydrodynamic lubrication contacts. Preliminary results at a twin-disk test rig are summarized to categorize friction and bulk temperature reduction by DLC coatings. Based on experiments at a gear efficiency test rig, the frictional power losses and bulk temperatures of DLC-coated gears are investigated, whereby load, speed, oil temperature and coatings are varied.

Findings

Experimental investigations at the gear efficiency test rig showed friction and bulk temperature reduction for all operating conditions of DLC-coated gears compared to uncoated gears. This effect was most pronounced for high load and high speed. A reduction of the mean gear coefficient of friction on average 25% and maximum 55% was found. A maximum reduction of bulk temperature of 15% was observed.

Practical implications

DLC-coated gears show a high potential for reducing friction and improving load-carrying capacity. However, the industrial implementation is restrained by the limited durability of coatings on gear flanks. Therefore, a further and overall consideration of key durability factors such as substrate material, pretreatment, coating parameters and gear geometry is necessary.

Originality/value

Thermal insulation effect of DLC coatings was shown by theoretical analyses and experimental investigations at model test rigs. Although trial tests on gears were conducted in literature, this study proves the friction reduction by DLC-coated gears for the first time systematically in terms of various operating conditions and coatings.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0257/

Details

Industrial Lubrication and Tribology, vol. 73 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

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Book part
Publication date: 21 February 2008

Abstract

Details

Modelling and Evaluating Treatment Effects in Econometrics
Type: Book
ISBN: 978-0-7623-1380-8

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Book part
Publication date: 1 January 2008

Ray Oakey and Gary Cook

A broad range of policy evaluations below is begun in Chapter 2 by Kate Johnston, Colette Henry and Simon Gillespie in their evaluation entitled ‘Encouraging Research and…

Abstract

A broad range of policy evaluations below is begun in Chapter 2 by Kate Johnston, Colette Henry and Simon Gillespie in their evaluation entitled ‘Encouraging Research and Development in Ireland's Biotechnology Enterprises’. This investigation critically evaluates Irish government policy towards biotechnology development over a preceding 10-year period. In Chapter 3, Anthony Ward, Sarah Cooper, Frank Cave and William Lucas examine ‘The Effect of Industrial Experience on Entrepreneurial Intent and Self-Efficacy in UK Engineering Undergraduates’ in a large-scale study that generally produces satisfactory results in terms of raising the profile of entrepreneurship among undergraduates. Deirdre Hunt, in Chapter 4, again focuses on the evolution of strategy in Ireland, this time towards the more general topic of new firm formation with a personal contribution entitled ‘Now You See Them — Now You Don’t: Paradoxes in Enterprise Development Strategy: The Case of the Disappearing Academic Start-Ups’.

Details

New Technology-Based Firms in the New Millennium
Type: Book
ISBN: 978-0-0805-5448-8

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