Search results

1 – 4 of 4
Book part
Publication date: 6 August 2014

Xiaowen Fu and Tae Hoon Oum

This chapter reviews the effects of air transport liberalization, and investigates the roles played by airport-airline vertical arrangements in liberalizing markets. Our…

Abstract

This chapter reviews the effects of air transport liberalization, and investigates the roles played by airport-airline vertical arrangements in liberalizing markets. Our investigation concludes that liberalization has led to substantial economic and traffic growth. Such positive outcomes are mainly due to increased competition and efficiency gains in the airline industry, and positive externalities to the overall economy. Liberalization allows airlines to optimize their networks, and thus may introduce substantial demand and financial uncertainty to airports. Vertical arrangements between airlines and airports may offer a wide range of benefits to the parties involved, yet such arrangements could also lead to airline entry barriers which reduce the effects of liberalization. Three approaches have been developed to model the effects of liberalization in complex market conditions, which include the analytical, econometric and computational network methods. These approaches should be selectively utilized in policy studies on liberalization.

Details

The Economics of International Airline Transport
Type: Book
ISBN: 978-1-78350-639-2

Keywords

Article
Publication date: 7 January 2021

Fatma Bakal, Ahmet Yapici, Muharrem Karaaslan and Oğuzhan Akgöl

The purpose of this paper is to investigate the effect of doping element on the microwave absorption performance of hexagonal nano boron nitride (h-nBN)-reinforced basalt…

Abstract

Purpose

The purpose of this paper is to investigate the effect of doping element on the microwave absorption performance of hexagonal nano boron nitride (h-nBN)-reinforced basalt fabric (BF)/epoxy composites. A new type of hybrid composite that will be produced by the use of boron nitride as an additive that leads to increased radar absorption capability will be developed and a new material that can be used in aeronautical radar applications.

Design/methodology/approach

This study is focused on the microwave absorption properties of h-nBN doped basalt fabric-reinforced epoxy composites. Basalt fabric (BF)/epoxy composites (pure composites) and the BF/h-nBN (1 Wt.% h-nBN doped composites) hybrid composites were fabricated by vacuum infusion method. Phase identification of the composites were performed using X-ray diffraction (XRD), the 2θ scan range was from 10 to 60 with the scanning speed of 3°/min and surface morphologies of the composites were investigated using scanning electron microscopy (SEM). Microwave properties of samples were investigated through transmission/reflection measurements in Agilent brand 2-Port PNA-L Network Analyzer in the frequency range of 3–18 GHz. The prepared sample is positioned between two horn antennas with and without metal plate.

Findings

Experimental results show that h-nBN doped composite was synthesized successfully and the produced hexagonal nano boron nitride-added fiber laminated composite material has good absorption behavior when they are used with metallic sheets and good for isolation applications at many points in the 3–18 GHz band.

Originality/value

This paper will contribute to the literature on the use of basalt fabric, which are new types of fibers, and hexagonal nano boron nitride and the effects of boron nitride on radar absorption properties of composite material. It presents detail characterization of each composite by using XRD and scanning electron microscopy.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 1
Type: Research Article
ISSN: 1748-8842

Keywords

Open Access
Article
Publication date: 15 February 2022

Martin Nečaský, Petr Škoda, David Bernhauer, Jakub Klímek and Tomáš Skopal

Semantic retrieval and discovery of datasets published as open data remains a challenging task. The datasets inherently originate in the globally distributed web jungle…

Abstract

Purpose

Semantic retrieval and discovery of datasets published as open data remains a challenging task. The datasets inherently originate in the globally distributed web jungle, lacking the luxury of centralized database administration, database schemes, shared attributes, vocabulary, structure and semantics. The existing dataset catalogs provide basic search functionality relying on keyword search in brief, incomplete or misleading textual metadata attached to the datasets. The search results are thus often insufficient. However, there exist many ways of improving the dataset discovery by employing content-based retrieval, machine learning tools, third-party (external) knowledge bases, countless feature extraction methods and description models and so forth.

Design/methodology/approach

In this paper, the authors propose a modular framework for rapid experimentation with methods for similarity-based dataset discovery. The framework consists of an extensible catalog of components prepared to form custom pipelines for dataset representation and discovery.

Findings

The study proposes several proof-of-concept pipelines including experimental evaluation, which showcase the usage of the framework.

Originality/value

To the best of authors’ knowledge, there is no similar formal framework for experimentation with various similarity methods in the context of dataset discovery. The framework has the ambition to establish a platform for reproducible and comparable research in the area of dataset discovery. The prototype implementation of the framework is available on GitHub.

Details

Data Technologies and Applications, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2514-9288

Keywords

Article
Publication date: 1 September 2002

Vangelis Tzouvelekas, Christos J. Pantzios and Christos Fotopoulos

Estimates the output‐oriented and input‐specific technical efficiency in two samples of Greek, durum wheat farms – organic and conventional ones – using Kalirajan and…

1377

Abstract

Estimates the output‐oriented and input‐specific technical efficiency in two samples of Greek, durum wheat farms – organic and conventional ones – using Kalirajan and Obwona’s stochastic varying coefficient regression model. Findings indicate that the organic wheat farms examined are relatively more efficient. Reasons may include lower profit margins and restrictions on inputs permitted, which may force organic farmers to be more cautious with input use. However, technical efficiency scores are still relatively low for both types of wheat farming. Therefore, considerable scope for cost reducing and farm income improvement may exist in both farming modes. This realization could prove crucial for the long‐run viability and the future course of organic wheat farming.

Details

British Food Journal, vol. 104 no. 8
Type: Research Article
ISSN: 0007-070X

Keywords

1 – 4 of 4