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Article
Publication date: 5 July 2011

Weishi Chen, Qunyu Xu, Huansheng Ning, Taosheng Wang and Jing Li

Foreign object debris (FOD) poses a significant hazard to aviation safety and brings huge economic losses to the aerospace industry due to aircraft damage and out‐of‐service…

1291

Abstract

Purpose

Foreign object debris (FOD) poses a significant hazard to aviation safety and brings huge economic losses to the aerospace industry due to aircraft damage and out‐of‐service delays. Different schemes and sensors have been utilized for FOD detection. This paper aims to look into a video‐based FOD detection system for airport runway security and propose a scheme for FOD surveillance network establishment.

Design/methodology/approach

The FOD detection algorithm for the system is analyzed in detail, including four steps of pre‐processing, background subtraction, post‐processing and FOD location.

Findings

The overall algorithm is applied to two sets of live video images. The results show that the algorithm is effective for FOD targets of different shades under different lighting conditions. The proposed system is also evaluated by the ground‐truth data collected at Nanyang Airport.

Practical implications

The runway security can be greatly increased by designing an affordable video‐based FOD detection system.

Originality/value

The paper presents critical techniques of video‐based FOD detection system. The scheme for FOD surveillance network, as a significant part of aviation risk management at airports, is applicable and extensible.

Details

Aircraft Engineering and Aerospace Technology, vol. 83 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

Open Access
Article
Publication date: 23 February 2024

Emmadonata Carbone, Donata Mussolino and Riccardo Viganò

This study investigates the relationship between board gender diversity (BGD) and the time to Initial Public Offering (IPO), which stands as an entrepreneurially risky choice…

Abstract

Purpose

This study investigates the relationship between board gender diversity (BGD) and the time to Initial Public Offering (IPO), which stands as an entrepreneurially risky choice, particularly challenging in family firms. We also investigate the moderating role of family ownership dispersion (FOD).

Design/methodology/approach

We draw on an integrated theoretical framework bringing together the upper echelons theory and the socio-emotional wealth (SEW) perspective and on hand-collected data on a sample of Italian family IPOs that occurred in the period 2000–2020. We employ ordinary least squares (OLS) regression and alternative model estimations to test our hypotheses.

Findings

BGD positively affects the time to IPO, thus, it increases the time required to go public. FOD negatively moderates this relationship. Our findings remain robust with different measures for BGD, FOD, and family business definition as well as with different econometric models.

Originality/value

The article develops literature on family firms and IPO and it enriches the academic debate about gender and IPOs in family firms. It adds to studies addressing the determinants of the time to IPO by incorporating gender diversity and the FOD into the discussion. Finally, it contributes to research on women and outcomes in family firms.

Details

Management Decision, vol. 62 no. 13
Type: Research Article
ISSN: 0025-1747

Keywords

Book part
Publication date: 18 July 2007

Frank Messner

In this chapter, the integrative methodological approach (IMA) of the research project GLOWA Elbe is introduced, which represents a scientific methodology to support water…

Abstract

In this chapter, the integrative methodological approach (IMA) of the research project GLOWA Elbe is introduced, which represents a scientific methodology to support water management under uncertainty regarding future paths of global change. The approach paves the way for integration of research work of many disciplines, of different assessment methods, of various policy fields, and the involvement of relevant stakeholders and decision makers. IMA can be roughly described by four research elements (scenario derivation, indicator and criteria identification, model-based impact analysis, and final scenario assessment based on combined benefit–cost and multi-criteria analysis), which lay the basis for the IMA activities of the global change research sequence. Its practical application is demonstrated by a case study on the Spree and Schwarze Elster river basins. Specific results of Chapter 4 (on scenario derivation) and Chapter 11 (on integrating economic evaluation into water management simulation) in this volume are picked up in order to focus on the illustration of the integrated assessment results for this German case study.

Details

Ecological Economics of Sustainable Watershed Management
Type: Book
ISBN: 978-1-84950-507-9

Book part
Publication date: 18 July 2007

Frank Messner

This chapter describes the scenario technique used for the integrative methodological approach (IMA) of the German global change project GLOWA Elbe. It is outlined how regional…

Abstract

This chapter describes the scenario technique used for the integrative methodological approach (IMA) of the German global change project GLOWA Elbe. It is outlined how regional scenarios are systematically derived to analyze water use conflicts and their resolution in the context of global change for the German Elbe river basin. Through the combination of frameworks of development and policy strategies a consistent set of developmental scenarios can be generated that makes it possible to examine the regional impact of policy strategies under conditions of different future global change development paths. The scenario analysis of the framework of development starts on the global level with qualitative IPCC storylines, translates them to the regional level, and quantifies their regional effects by means of modeling and statistical estimation methods. The policy strategies are derived in close cooperation with regional stakeholders.

Details

Ecological Economics of Sustainable Watershed Management
Type: Book
ISBN: 978-1-84950-507-9

Article
Publication date: 8 May 2017

Sidney Anderson and Jeffery Smith

The “services triangle” is a dynamic model in which three interlinked entities (customer, employee and firm) combine to create three dyads [employee-firm (EF), customer-firm (CF…

1788

Abstract

Purpose

The “services triangle” is a dynamic model in which three interlinked entities (customer, employee and firm) combine to create three dyads [employee-firm (EF), customer-firm (CF) and customer-employee (CE)] that work together to deliver services. This study aims to determine whether significant differences exist vis-à-vis the impact of EF, CF and CE dyads on the service experience.

Design/methodology/approach

Empirical evidence from data garnered from 398 surveys was used to test a conceptual model. To test the hypotheses, like-signed first-order dyads were constructed and combined to create second-order dyads, and analysis of variance and post-hoc tests (least significant differences) were used to investigate whether differences among the second-order dyads exist.

Findings

The analysis reveals the differential impact of the three services triangle dyads on the service experience. Specifically, customers’ perception of EF fit appears to have the greatest impact on customers’ evaluation of the service experience, followed by CF and CE fit.

Research limitations/implications

The main implication is that this paper extends conceptual research by providing empirical evidence that the EF dyad is the foundation of the services triangle. The limitations are based primarily on methodology, where the use of a survey to collect data rules out the potential generalizations of true cause and effect while also potentially being subject to common method bias.

Practical implications

Managers should realize that fit within some dyads is more instrumental in determining the service experience than fit within others. A number of managerial implications are proposed and discussed.

Originality/value

Prior research has neither empirically examined the services triangle nor whether significant differences exists among the impact of its dyads on the service experience. Insights from various literatures, the application of the balance theory and the construction of first- and second-order dyads enables an investigation of the various relational patterns contained in the services triangle.

Details

Journal of Services Marketing, vol. 31 no. 3
Type: Research Article
ISSN: 0887-6045

Keywords

Article
Publication date: 24 July 2023

Rachaita Dutta, Soumik Das, Shishir Gupta, Aditi Singh and Harsh Chaudhary

The purpose of this study is to analyze the thermo-diffusion process in a semi-infinite nonlocal fiber-reinforced double porous thermoelastic diffusive material with voids…

Abstract

Purpose

The purpose of this study is to analyze the thermo-diffusion process in a semi-infinite nonlocal fiber-reinforced double porous thermoelastic diffusive material with voids (FRDPTDMWV) in light of the fractional-order Lord–Shulman thermo-elasto-diffusion (LSTED) model. By virtue of Eringen’s nonlocal elasticity theory, the governing equations for the considered material are developed. The free surface of the substrate is governed by the inclined mechanical load and thermal and chemical shocks.

Design/methodology/approach

With the aid of the normal mode technique, the solutions of the nondimensional coupled governing equations have been obtained.

Findings

The expressions of field variables are obtained analytically. By using MATHEMATICA software, various graphical implementations are presented to describe the impacts of angle of inclination, fractional-order and nonlocality parameters. The present model is also validated on the basis of some comparative studies with some preestablished cases.

Originality/value

As observed from the literature survey, many different studies have been carried out by taking into account the deformation analysis in nonlocal double porous thermoelastic material structures and thermo-mechanical interaction in fiber-reinforced medium under fractional-order thermoelasticity theories. However, to the best of the authors’ knowledge, no research emphasizing the thermo-elasto-diffusive interactions in a nonlocal FRDPTDMWV has been carried out. Moreover, the effect of fractional-order LSTED theory on fiber-reinforced thermoelastic diffusive half-space with double porosity has not been illuminated till now, which significantly defines the novelty of the conducted research.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 11
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 10 August 2015

Mica Grujicic, Jennifer Snipes, Ramin Yavari, S. Ramaswami and Rohan Galgalikar

The purpose of this paper is to prevent their recession caused through chemical reaction with high-temperature water vapor, SiC-fiber/SiC-matrix ceramic-matrix composite (CMC…

Abstract

Purpose

The purpose of this paper is to prevent their recession caused through chemical reaction with high-temperature water vapor, SiC-fiber/SiC-matrix ceramic-matrix composite (CMC) components used in gas-turbine engines are commonly protected with so-called environmental barrier coatings (EBCs). EBCs typically consist of three layers: a top thermal and mechanical protection coat; an intermediate layer which provides environmental protection; and a bond coat which assures good EBC/CMC adhesion. The materials used in different layers and their thicknesses are selected in such a way that the coating performance is optimized for the gas-turbine component in question.

Design/methodology/approach

Gas-turbine engines, while in service, often tend to ingest various foreign objects of different sizes. Such objects, entrained within the gas flow, can be accelerated to velocities as high as 600 m/s and, on impact, cause substantial damage to the EBC and SiC/SiC CMC substrate, compromising the component integrity and service life. The problem of foreign object damage (FOD) is addressed in the present work computationally using a series of transient non-linear dynamics finite-element analyses. Before such analyses could be conducted, a major effort had to be invested toward developing, parameterizing and validating the constitutive models for all attendant materials.

Findings

The computed FOD results are compared with their experimental counterparts in order to validate the numerical methodology employed.

Originality/value

To the authors’ knowledge, the present work is the first reported study dealing with the computational analysis of the FOD sustained by CMCs protected with EBCs.

Details

Multidiscipline Modeling in Materials and Structures, vol. 11 no. 2
Type: Research Article
ISSN: 1573-6105

Keywords

Book part
Publication date: 24 October 2019

Venkataramanaiah Malepati, Madhavi Latha Challa and Siva Nageswara Rao Kolusu

This study is intended to investigate the volatility patterns in Bombay Stock Exchange Limited Sensitivity Index (BSE Sensex) based on time series data collected for 10 years…

Abstract

This study is intended to investigate the volatility patterns in Bombay Stock Exchange Limited Sensitivity Index (BSE Sensex) based on time series data collected for 10 years period of time. To reach out the predefined objectives of the study, the authors have employed generalized autoregressive conditional heteroscedastic models. The study revealed that the presence of heteroscedasticiy is found in BSE Sensex. Further, the model produced highly accurate results when the researchers compared the estimated results from actual. Furthermore, the volatility of BSE Sensex has shown the features of clustering and significant time varying. Moreover, the model has indicated that there is a positive correlation between daily stock returns and the BSE Sensex volatility.

Article
Publication date: 11 August 2023

Myrel Tiemann, Markus Clemens and Benedikt Schmuelling

This paper aims to present a fast and modular framework implementation for the thermal analyses of foreign metal objects in the context of wireless power transfer (WPT) to…

Abstract

Purpose

This paper aims to present a fast and modular framework implementation for the thermal analyses of foreign metal objects in the context of wireless power transfer (WPT) to evaluate whether they pose a hazard to the system. This framework serves as a decision-making tool for determining the necessity of foreign object detection in certain applications and at certain transmitted power levels.

Design/methodology/approach

To assess the necessity of implementing foreign object detection, the considered WPT system is modeled, and Arnoldi-Krylov-based model order reduction is applied to generate separate reduced models of the ground and vehicle modules of the WPT system. This enables interoperable evaluations to be conducted. Further discussion on the implementation details of the system-level simulations used to evaluate the electrical and thermal characteristics is provided. The resulting modular implementation allows for efficient evaluation of the thermal behavior of the wireless charging system at various transferred power levels and under various boundary conditions.

Findings

Based on the transferred power level, the WPT model, the relative positioning between the vehicle and the charging pad and the charging time, it may be necessary to divide the area of the charging pad into multiple regions for the purpose of implementing foreign object detection.

Originality/value

While the tools and fundamentals of thermal analysis are widely known and used, their application to high-power WPT systems for electric vehicles has not yet been thoroughly discussed in this form in the literature. The approach presented in this paper is not limited to the specific WPT model discussed but rather is directly applicable to other WPT models as well.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 42 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

Book part
Publication date: 18 July 2007

Frank Messner, Hagen Koch and Michael Kaltofen

In this chapter it is shown how economic evaluation algorithms of water use can be integrated into a long-term water management model such that surface-water availability and…

Abstract

In this chapter it is shown how economic evaluation algorithms of water use can be integrated into a long-term water management model such that surface-water availability and economic evaluation of various levels of water availability to different uses can be modeled simultaneously. This approach makes it possible to include essential features of economic analyses of water use into water resource modeling and thus improves the capability of such models to support decision making in water management. This is especially relevant for the implementation of the Water Framework Directive, which requires economic analyses to be included in the decision process about future water management strategies.

The water management simulation model WBalMo is presented and the integration of economic-evaluation algorithms is demonstrated for the examples of surface-water use for fish farming and for filling open-cast mining pits in order to achieve acceptable water-quality levels in the emerging pit lakes. Results of applying this integrated evaluation approach are shown for different water management scenarios under conditions of global change in the East German Spree and Schwarze Elster river basins, where water scarcity is an urgent issue. Among the lessons which are drawn by the authors one lesson reads that integrating economic evaluation algorithms into a pre-existing model might bring enormous problems. Therefore, such model approaches should be developed together by water engineers and economists in an interdisciplinary endeavor right from the start.

Details

Ecological Economics of Sustainable Watershed Management
Type: Book
ISBN: 978-1-84950-507-9

1 – 10 of 154