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Article
Publication date: 1 August 1999

H.G. Visser

This study presents a preliminary evaluation of the application of Thrust Vectoring (TV) technology for improving windshear recovery of civil aircraft in microburst windshear…

434

Abstract

This study presents a preliminary evaluation of the application of Thrust Vectoring (TV) technology for improving windshear recovery of civil aircraft in microburst windshear encounters. A numerical trajectory optimization technique based on the method of multiple shooting is applied to achieve a microburst escape with minimal loss of altitude for a Boeing 727 type aircraft. Although the application of TV does result in a slight improvement in recovery altitude, there is also a price to be paid in the sense that TV utilization significantly hampers the ability to gain specific energy during recovery. Maintaining an energy buffer during a microburst encounter is highly desirable to achieve robustness with respect to uncertainness in windshear size and strength. TV aided windshear recovery has also been compared with an alternative approach to improve the windshear survivability capability, namely, the application of lateral maneuvering. The comparison shows that lateral maneuvering is not only a far more effective means to improve the recovery altitude, it also vastly improves energy preservation. In a view of the results established in this study, we feel that TV does not hold out great promise as a useful means to truly improve windshear recovery.

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Aircraft Engineering and Aerospace Technology, vol. 71 no. 4
Type: Research Article
ISSN: 0002-2667

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Book part
Publication date: 25 October 2014

Huub J. M. Ruël and Robin Visser

In a globalized world where emerging markets are more important than ever, there is an increasing pressure on international businesses and governments to work together. The set of…

Abstract

Purpose

In a globalized world where emerging markets are more important than ever, there is an increasing pressure on international businesses and governments to work together. The set of facilities known as commercial diplomacy combines the interests of both by highlighting new markets and investment opportunities.

Methodology/approach

In this chapter, we present a literature review based on 56 relevant publications to assess what we currently know of this important activity.

Findings

The results indicate that research on commercial diplomacy consists of many subtopics, resulting in a patchy understanding of the topic as a whole.

Research limitations/implications

We discuss why integrative research focusing on the business–government relationship and the organization and the value of commercial diplomacy are needed from an international business perspective.

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Multinational Enterprises, Markets and Institutional Diversity
Type: Book
ISBN: 978-1-78441-421-4

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Article
Publication date: 1 April 2002

I.J.B.F. Adan and J.M.H. Vissers

Admissions planning decides on the number of patients admitted for a specialty each day, but also on the mix of patients admitted. Within a specialty different categories of…

3617

Abstract

Admissions planning decides on the number of patients admitted for a specialty each day, but also on the mix of patients admitted. Within a specialty different categories of patients can be distinguished on behalf of their requirement of resources. The type of resources required for an admission may involve beds, operating theatre capacity, nursing capacity and intensive care beds. The mix of patients is, therefore, an important decision variable for the hospital to manage the workload of the inflow of patients. In this paper we will consider the following planning problem: how can a hospital generate an admission profile for a specialty, given a target patient throughput and utilization of resources, while satisfying given restrictions? For this planning problem, we will develop an integer linear programming model, that has been tested in a pilot setting in a hospital. The paper includes an analysis of the planning problem, a description of the model developed, an application of a specialty orthopaedics, and a discussion of the results obtained.

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International Journal of Operations & Production Management, vol. 22 no. 4
Type: Research Article
ISSN: 0144-3577

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Emotional and Behavioural Difficulties in Mainstream Schools
Type: Book
ISBN: 978-0-76230-722-7

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Book part
Publication date: 26 September 2022

Michelle Dibben and Howard Youngs

Collaboration is viewed as an essential ingredient for education systems and school improvement. Collaborative leadership has both emergent and intentional components (Woods &

Abstract

Collaboration is viewed as an essential ingredient for education systems and school improvement. Collaborative leadership has both emergent and intentional components (Woods & Roberts, 2018). Collaborative practices can emerge over time as teachers and schools work together, and intentional interventions and decisions can either support this emergence and/or work against it. In this chapter, we discuss the New Zealand case of collaboration between schools. The context is situated in policy reform associated with an incentivized and voluntary programme that groups of schools could participate in. The programme, communities of schools (CoLs), was implemented in 2014 and continues at the time of writing this chapter. We draw on critical commentary of the programme, as well as the small number of research studies available. The experienced way of CoLs is replete with tensions. These are illustrated with the help of Hoods’ (1998) social regulation and cohesion matrix. Rather than locate the New Zealand case in one quadrant of the matrix, we illustrate how multiple aspects of Hoods’ matrix (1998) have been and are currently in play regarding collaboration between schools in New Zealand.

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School-to-School Collaboration: Learning Across International Contexts
Type: Book
ISBN: 978-1-80043-669-5

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Book part
Publication date: 10 December 2018

Huub Ruël

Abstract

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Making Trade Missions Work: A Best Practice Guide to International Business and Commercial Diplomacy
Type: Book
ISBN: 978-1-78635-471-6

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Article
Publication date: 1 March 1991

Josephine J. Prior

Outlines the development of the Building Research EstablishmentEnvironmental Assessment Method (BREEAM), and discusses the operatingprocess behind the first version BREEAM 1/90…

681

Abstract

Outlines the development of the Building Research Establishment Environmental Assessment Method (BREEAM), and discusses the operating process behind the first version BREEAM 1/90. Examines the objectives and criteria for BREEAM, highlighting its functions to provide recognition for buildings which are friendlier to the global environment than normal, so stimulating a market for them; to raise awareness of the dominant role which the use of energy in buildings plays in global warming; to provide a common set of targets and standards. Explores the environmental issues addressed in BREEAM, concentrating on global, neighbourhood and internal issues. Suggests future issues and comments on the assessment process.

Details

Structural Survey, vol. 9 no. 3
Type: Research Article
ISSN: 0263-080X

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Article
Publication date: 3 November 2022

Emre Aydoğan and Cem Cetek

The purpose of this paper is to create a flight route optimization for all flights that aims to minimize the total cost consists of fuel cost, ground delay cost and air delay cost…

215

Abstract

Purpose

The purpose of this paper is to create a flight route optimization for all flights that aims to minimize the total cost consists of fuel cost, ground delay cost and air delay cost over the fixed route and free route airspaces.

Design/methodology/approach

Efficient usage of current available airspace capacity becomes more and more important with the increasing flight demands. The efficient capacity usage of an airspace is generally in contradiction to optimum flight efficiency of a single flight. It can only be achieved with the holistic approach that focusing all flights over mixed airspaces and their routes instead of single flight route optimization for a single airspace. In the scope of this paper, optimization methods were developed to find the best route planning for all flights considering the benefits of all flights not only a single flight. This paper is searching for an optimization to reduce the total cost for all flights in mixed airspaces. With the developed optimization models, the determination of conflict-free optimum routes and delay amounts was achieved with airway capacity and separation minimum constraints in mixed airspaces. The mathematical model and the simulated annealing method were developed for these purposes.

Findings

The total cost values for flights were minimized by both developed mathematical model and simulated annealing algorithm. With the mathematical model, a reduction in total route length of 4.13% and a reduction in fuel consumption of 3.95% was achieved in a mixed airspace. The optimization algorithm with simulated annealing has also 3.11% flight distance saving and 3.03% fuel consumption enhancement.

Research limitations/implications

Although the wind condition can change the fuel consumption and flight durations, the paper does not include the wind condition effects. If the wind condition effect is considered, the shortest route may not always cause the least fuel consumption especially under the head wind condition.

Practical implications

The results of this paper show that a flight route optimization as a holistic approach considering the all flight demand information enhances the fuel consumption and flight duration. Because of this reason, the developed optimization model can be effectively used to minimize the fuel consumption and reduce the exhaust emissions of aircraft.

Originality/value

This paper develops the mathematical model and simulated annealing algorithm for the optimization of flight route over the mixed airspaces that compose of fixed and free route airspaces. Each model offers the best available and conflict-free route plan and if necessary required delay amounts for each demanded flight under the airspace capacity, airspace route structure and used separation minimum for each airspace.

Details

Aircraft Engineering and Aerospace Technology, vol. 95 no. 4
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 1 May 1992

J.A. VISSER and H. ROLFES

By modelling the unsteady heat transfer in liquid gas tanks, the temperature distribution in the tank as well as the heat flux reaching the liquid gas can be predicted. Knowledge…

89

Abstract

By modelling the unsteady heat transfer in liquid gas tanks, the temperature distribution in the tank as well as the heat flux reaching the liquid gas can be predicted. Knowledge of the temperature distribution and heat flux can be used to predict evaporation losses from the tank. By minimizing the evaporation losses, the thermal design of a gas tank can be optimized. This paper presents a finite difference simulation of the unsteady three‐dimensional heat transfer in gas tanks and an optimized configuration. The numerical procedure accounts for radiation from the sun as well as radiative and convective heat transfer with the environment. A non‐uniform grid is used because the tank consists of several different materials of varying dimensions and properties. Geometrical effects such as variations in the thickness of the insulation material and the diameter and height of the tanks are also studied in an attempt to optimize the design configuration.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 2 no. 5
Type: Research Article
ISSN: 0961-5539

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Book part
Publication date: 11 July 2001

John Visser, Harry Daniels and Ted Cole

Abstract

Details

Emotional and Behavioural Difficulties in Mainstream Schools
Type: Book
ISBN: 978-0-76230-722-7

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