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1 – 10 of 15
Article
Publication date: 28 October 2021

Joaquim Vasconcelos Reinolds de Sousa and Pedro Gamboa

The purpose of this paper is to generate optimised trajectories for an unmanned aerial vehicle (UAV) during a forest fire detection mission. It is assumed that the UAV flies 3D…

139

Abstract

Purpose

The purpose of this paper is to generate optimised trajectories for an unmanned aerial vehicle (UAV) during a forest fire detection mission. It is assumed that the UAV flies 3D curvature-constrained Dubins manoeuvres and has a limited amount of battery energy that prevents it from covering the entire search area in a single trip.

Design/methodology/approach

In this paper, the search area is discretised into a grid of multiple targets, and each target assigned with a score that is proportional to the time elapsed since the last UAV visit. This problem, known as Dubins Airplane Orienteering Problem, consists of finding the number and order of targets to visit and the UAV heading at each target that maximises the total trip score without exceeding the UAV battery energy. The solution is found using the Randomised Variable Neighbourhood Search metaheuristic. All target scores are updated after each trajectory generation according to the elapsed time since the last UAV visit.

Findings

The proposed approach produced feasible results when generating optimised trajectories for a fire detection mission context where energy battery constraints are important.

Practical implications

The authors carry out the planning of UAV missions with limited amounts of onboard energy such as a real fire detection mission using a single electric propulsion and fixed-wing UAV.

Originality/value

This paper introduces an energy-based approach to the Dubins Airplane Orienteering Problem, which takes into account the UAV performance and energy budget when generating optimised trajectories.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 4 May 2021

Luitpold Babel

A major challenge for mission planning of aircraft is to generate flight paths in highly dynamic environments. This paper presents a new approach for online flight path planning…

Abstract

Purpose

A major challenge for mission planning of aircraft is to generate flight paths in highly dynamic environments. This paper presents a new approach for online flight path planning with flight time constraints for fixed-wing UAVs. The flight paths must take into account the kinematic restrictions of the vehicle and be collision-free with terrain, obstacles and no-fly areas. Moreover, the flight paths are subject to time constraints such as predetermined time of arrival at the target or arrival within a specified time interval.

Design/methodology/approach

The proposed flight path planning algorithm is an evolution of the well-known RRT* algorithm. It uses three-dimensional Dubins paths to reflect the flight capabilities of the air vehicle. Requirements for the flight time are realized by skillfully concatenating two rapidly exploring random trees rooted in the start and target point, respectively.

Findings

The approach allows to consider static obstacles, obstacles which might pop up unexpectedly, as well as moving obstacles. Targets might be static or moving with constantly changing course. Even a change of the target during flight, a change of the target approach direction or a change of the requested time of arrival is included.

Originality/value

The capability of the flight path algorithm is demonstrated by simulation results. Response times of fractions of a second qualify the algorithm for real-time applications in highly dynamic scenarios.

Details

International Journal of Intelligent Unmanned Systems, vol. 10 no. 4
Type: Research Article
ISSN: 2049-6427

Keywords

Article
Publication date: 1 March 1985

Yash Gupta and Wing Sing Chow

This article surveys the literature dealing with theory and applications of life cycle costing (LCC). It deals with the literature published in the last 25 years and provides 667…

1047

Abstract

This article surveys the literature dealing with theory and applications of life cycle costing (LCC). It deals with the literature published in the last 25 years and provides 667 references.

Details

International Journal of Quality & Reliability Management, vol. 2 no. 3
Type: Research Article
ISSN: 0265-671X

Article
Publication date: 1 February 1988

David Macarov

The author argues that we must stop and take a look at what our insistence on human labour as the basis of our society is doing to us, and begin to search for possible…

2428

Abstract

The author argues that we must stop and take a look at what our insistence on human labour as the basis of our society is doing to us, and begin to search for possible alternatives. We need the vision and the courage to aim for the highest level of technology attainable for the widest possible use in both industry and services. We need financial arrangements that will encourage people to invent themselves out of work. Our goal, the article argues, must be the reduction of human labour to the greatest extent possible, to free people for more enjoyable, creative, human activities.

Details

International Journal of Sociology and Social Policy, vol. 8 no. 2/3/4
Type: Research Article
ISSN: 0144-333X

Keywords

Book part
Publication date: 26 September 2024

Michael Matthews, Thomas Kelemen, M. Ronald Buckley and Marshall Pattie

Patriotism is often described as the “love of country” that individuals display in the acclamation of their national community. Despite the prominence of this sentiment in various…

Abstract

Patriotism is often described as the “love of country” that individuals display in the acclamation of their national community. Despite the prominence of this sentiment in various societies around the world, organizational research on patriotism is largely absent. This omission is surprising because entrepreneurs, human resource (HR) divisions, and firms frequently embrace both patriotism and patriotic organizational practices. These procedures include (among other interventions) national symbol embracing, HR practices targeted toward military members and first responders, the adulation of patriots and celebration of patriotic events, and patriotic-oriented corporate social responsibility (CSR). Here, the authors argue that research on HR management and organization studies will likely be further enhanced with a deeper understanding of the national obligation that can spur employee productivity and loyalty. In an attempt to jumpstart the collective understanding of this phenomenon, the authors explore the antecedents of patriotic organizational practices, namely, the effects of founder orientation, employee dispersion, and firm strategy. It is suggested that HR practices such as these lead to a patriotic organizational image, which in turn impacts investor, customer, and employee responses. Notably, the effect of a patriotic organizational image on firm-related outcomes is largely contingent on how it fits with the patriotic views of other stakeholders, such as investors, customers, and employees. After outlining this model, the authors then present a thought experiment of how this model may appear in action. The authors then discuss ways the field can move forward in studying patriotism in HR management and organizational contexts by outlining several future directions that span multiple levels (i.e., micro and macro). Taken together, in this chapter, the authors introduce a conversation of something quite prevalent and largely unheeded – the patriotic organization.

Details

Research in Personnel and Human Resources Management
Type: Book
ISBN: 978-1-83797-889-2

Keywords

Article
Publication date: 1 June 2002

Barrie O. Pettman and Richard Dobbins

This issue is a selected bibliography covering the subject of leadership.

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Abstract

This issue is a selected bibliography covering the subject of leadership.

Details

Equal Opportunities International, vol. 21 no. 4/5/6
Type: Research Article
ISSN: 0261-0159

Keywords

Article
Publication date: 16 November 2018

Michael J. McCord, Sean MacIntyre, Paul Bidanset, Daniel Lo and Peadar Davis

Air quality, noise and proximity to urban infrastructure can arguably have an important impact on the quality of life. Environmental quality (the price of good health) has become…

Abstract

Purpose

Air quality, noise and proximity to urban infrastructure can arguably have an important impact on the quality of life. Environmental quality (the price of good health) has become a central tenet for consumer choice in urban locales when deciding on a residential neighbourhood. Unlike the market for most tangible goods, the market for environmental quality does not yield an observable per unit price effect. As no explicit price exists for a unit of environmental quality, this paper aims to use the housing market to derive its implicit price and test whether these constituent elements of health and well-being are indeed capitalised into property prices and thus implicitly priced in the market place.

Design/methodology/approach

A considerable number of studies have used hedonic pricing models by incorporating spatial effects to assess the impact of air quality, noise and proximity to noise pollutants on property market pricing. This study presents a spatial analysis of air quality and noise pollution and their association with house prices, using 2,501 sale transactions for the period 2013. To assess the impact of the pollutants, three different spatial modelling approaches are used, namely, ordinary least squares using spatial dummies, a geographically weighted regression (GWR) and a spatial lag model (SLM).

Findings

The findings suggest that air quality pollutants have an adverse impact on house prices, which fluctuate across the urban area. The analysis suggests that the noise level does matter, although this varies significantly over the urban setting and varies by source.

Originality/value

Air quality and environmental noise pollution are important concerns for health and well-being. Noise impact seems to depend not only on the noise intensity to which dwellings are exposed but also on the nature of the noise source. This may suggest the presence of other externalities that arouse social aversion. This research presents an original study utilising advanced spatial modelling approaches. The research has value in further understanding the market impact of environmental factors and in providing findings to support local air zone management strategies, noise abatement and management strategies and is of value to the wider urban planning and public health disciplines.

Details

Journal of European Real Estate Research, vol. 11 no. 3
Type: Research Article
ISSN: 1753-9269

Keywords

Article
Publication date: 1 December 1959

G.V.E. Thompson

The present stage of development of vehicles for space exploration corresponds to some degree to that of the aeroplane in 1905. The programme of the U.S. National Aeronautics and…

Abstract

The present stage of development of vehicles for space exploration corresponds to some degree to that of the aeroplane in 1905. The programme of the U.S. National Aeronautics and Space Administration in the fields of space science research, applications of Earth satellites, manned exploration of space, and vehicle development are reviewed. International co‐operation in space exploration is desirable, particularly as regards exchange of information, exchanges of scientists, co‐ordination of national programmes, and institution of co‐operative programmes.

Details

Aircraft Engineering and Aerospace Technology, vol. 31 no. 12
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 14 March 2023

Nilay Bıçakcıoğlu-Peynirci and Robert E. Morgan

While the servitization concept has gained increasing attention in the domestic marketing literature, there is more limited knowledge with respect to its implications within the…

577

Abstract

Purpose

While the servitization concept has gained increasing attention in the domestic marketing literature, there is more limited knowledge with respect to its implications within the international context. The purpose of this paper is to examine the servitization concept in the international context considering its boundary conditions and its effects on firm performance. Relying on the resource-based view and the boundary conditions function, the authors aim to identify a set of research gaps focusing on how strategic resource decisions (i.e. slack resources and digital marketing capabilities) help industrial firms to provide different types of service offerings (i.e. services in support of product (SSPs) and services in support of client's actions (SSCs)) that leverage their performance in international markets.

Design/methodology/approach

The authors illustrate international servitization strategies and the boundaries of servitization activities that firms employ through a series of case vignettes. The authors derive a conceptual framework, serving as a guideline for future research endeavors.

Findings

The authors indicate the importance of servitization strategies in international markets and identify eight research gaps, which help to build an agenda for future research. Key differences between international servitization strategies and strategic resource decisions are addressed through illustrative case vignettes from different industries.

Practical implications

The insights from this work inform marketing executives about how international servitization strategies are influential in the context of overseas markets by characterizing the servitization concept and elaborating upon the specific resources and capabilities that underpin its execution in foreign markets.

Originality/value

This conceptual paper provides a comprehensive understanding of international servitization strategies in overseas markets and identifies several research paths that contribute to the complex nature of servitization in the international context and help scholars spot gaps and research questions worthy of investigation.

Details

International Marketing Review, vol. 40 no. 2
Type: Research Article
ISSN: 0265-1335

Keywords

Article
Publication date: 8 October 2018

Luitpold Babel

The purpose of this paper is to present a new approach for finding a minimum-length trajectory for an autonomous unmanned air vehicle or a long-range missile from a release point…

Abstract

Purpose

The purpose of this paper is to present a new approach for finding a minimum-length trajectory for an autonomous unmanned air vehicle or a long-range missile from a release point with specified release conditions to a destination with specified approach conditions. The trajectory has to avoid obstacles and no-fly zones and must take into account the kinematic constraints of the air vehicle.

Design/methodology/approach

A discrete routing model is proposed that represents the airspace by a sophisticated network. The problem is then solved by applying standard shortest-path algorithms.

Findings

In contrast to the most widely used grids, the generated networks allow arbitrary flight directions and turn angles, as well as maneuvers of different strengths, thus fully exploiting the flight capabilities of the aircraft. Moreover, the networks are resolution-independent and provide high flexibility by the option to adapt density.

Practical implications

As an application, a concept for in-flight replanning of flight paths to changing destinations is proposed. All computationally intensive tasks are performed in a pre-flight planning prior to the launch of the mission. The in-flight planning is based entirely on precalculated data, which are stored in the onboard computer of the air vehicle. In particular, no path finding algorithms with high or unpredictable running time and uncertain outcome have to be applied during flight.

Originality/value

The paper presents a new network-based algorithm for flight path optimization that overcomes weaknesses of grid-based approaches and allows high-quality solutions. The method can be applied for quick in-flight replanning of flight paths.

Details

Aircraft Engineering and Aerospace Technology, vol. 90 no. 8
Type: Research Article
ISSN: 1748-8842

Keywords

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