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Article

Valentin Bertsch, Martin Treitz, Jutta Geldermann and Otto Rentz

Emergency situations may differ in many ways but they share some common characteristics, such as the sudden onset and the need to transparently evaluate various usually…

Abstract

Purpose

Emergency situations may differ in many ways but they share some common characteristics, such as the sudden onset and the need to transparently evaluate various usually conflicting objectives. In nuclear power generation, however, emergency situations constitute a special challenge. The focus of this paper is to highlight the role of multi‐criteria decision analysis (MCDA) in nuclear emergency and recovery management on the basis of a hypothetical case study.

Design/methodology/approach

Multi‐attribute value theory as one field of research within MCDA is introduced. Special emphasis is placed on the modelling of the decision makers' preferences which is a crucial part in any multi‐criteria analysis. A central aim is to facilitate the preference elicitation in group decision processes.

Findings

The management of emergency situations in nuclear power generation necessitates the consideration of technical, economic, environmental, socio‐psychological and political aspects. Furthermore, various stakeholder and expert groups with diverse background knowledge and different views, responsibilities and interests are involved in such a decision‐making process. MCDA can help to take into account various incommensurable aspects and the subjective preferences of the decision makers and thus contribute to transparency and traceability of decision‐making processes. Since the preference parameters are inherently afflicted with uncertainties, thorough sensitivity analyses are important to visualise the impact of the uncertainties in an understandable way.

Originality/value

A new approach to sensitivity analysis is proposed, allowing one to comprehensibly visualise and communicate the impact of the uncertainties associated with the subjective preference parameters on the results of the decision analysis.

Details

International Journal of Energy Sector Management, vol. 1 no. 4
Type: Research Article
ISSN: 1750-6220

Keywords

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Article

Frank Holzäpfel

In this study, 12 potential wake vortex encounters that were reported at a major European airport have been investigated. Because almost all encounters occurred in ground…

Abstract

Purpose

In this study, 12 potential wake vortex encounters that were reported at a major European airport have been investigated. Because almost all encounters occurred in ground proximity, most pilots conducted a go-around. The primary purpose of this study is to discriminate between incidents caused by wake vortices or rather by effects like wind shear or turbulence. Detailed knowledge of real-world encounter scenarios and identification of worst-case conditions during the final approach constitute highly relevant background information to assess the standard scenario used for the definition of revised wake turbulence separations.

Design/methodology/approach

Wake vortex predictions using the probabilistic two-phase wake vortex model (P2P) are used to investigate the incidents in detail by using data from the flight data recorder, meteorological instrumentation at the airport and numerical weather prediction.

Findings

In the best documented cases, the flight tracks through the vortices could be reconstructed in good agreement with wake vortex predictions and recorded aircraft reactions. Out of the eight plausible wake vortex encounters, five were characterized by weak crosswinds below 1.5 m/s combined with tailwinds. This meteorological situation appears favourable for encounters because, on the one hand, weak crosswinds may compensate the self-induced lateral propagation of the upwind vortex, such that it may hover over the runway directly in the flight path of the following aircraft. On the other hand, tailwinds limit the propagation of the so-called end effects caused by the breakdown of lift during touchdown.

Practical implications

The installation of plate lines beyond the runway tails may improve safety by reducing the number of wake vortex encounters.

Originality/value

The conducted investigations provide high originality and value for both science and operational application.

Details

Aircraft Engineering and Aerospace Technology, vol. 89 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

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Article

Wang Xinlong, Ji Jiaxing and Li Yafeng

Troposphere delay is one of the important error sources in global positioning system (GPS) positioning. The purpose of this paper is to analyze the accuracy and…

Abstract

Purpose

Troposphere delay is one of the important error sources in global positioning system (GPS) positioning. The purpose of this paper is to analyze the accuracy and adaptability of GPS troposphere error correction models, and to provide theoretic foundation for model selection in GPS accurate positioning.

Design/methodology/approach

The principle of troposphere delay error effecting on GPS signals is theoretically analyzed. The model peculiarity and modeling method of the four common troposphere delay correction models: Hopfield, Saastamoinen, Black, and Egnos models are discussed detailedly. With the measurement data from Crustal Dynamics Data Information System of the technical support institution for GPS, the accuracy and applicability of the four models are quantificationally studied.

Findings

For a low elevation, Hopfield, Saastamoinen, and Black models show great agreement with each other, and have quite high precision. In the zenith direction, the maximal troposphere delay error of three models are all less than 1 dm, but Black and Hopfield models have higher precision than Saastamoinen model. Black model can be regarded as the improved form of Hopfield model: for a high elevation, precision of two models are close, while for a low elevation, Black model shows to be more effective than Hopfield model. The precision of Egnos model is quite lower than that of Black, Hopfield, and Saastamoinen models. However, Egnos model can be a better choice when it is difficult to obtain real‐time meteorological data in certain application environment.

Originality/value

This paper makes thorough research on GPS troposphere delay error correction models. The conclusions are presented for selecting troposphere delay models, which are useful for practical engineering application.

Details

Aircraft Engineering and Aerospace Technology, vol. 81 no. 5
Type: Research Article
ISSN: 0002-2667

Keywords

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Article

Zhou Jiabin and Zhang Haifu

In this paper, the relationship between meteorological conditions and diseases is investigated. The relative fitting errors for nine kinds of diseases are within the limit…

Abstract

In this paper, the relationship between meteorological conditions and diseases is investigated. The relative fitting errors for nine kinds of diseases are within the limit of 0.048‐0.228. These results are the bases of researches of mechanism and a component of the numerical model which has been used in the prediction of diseases.

Details

Kybernetes, vol. 33 no. 2
Type: Research Article
ISSN: 0368-492X

Keywords

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Article

Reem S. Ettouney, Farouq S. Mjalli, John G. Zaki, Mahmoud A. El‐Rifai and Hisham M. Ettouney

The objective of this study is to develop and validate a neural‐based modelling methodology applicable to site‐specific short‐ and medium‐term ozone concentration…

Abstract

Purpose

The objective of this study is to develop and validate a neural‐based modelling methodology applicable to site‐specific short‐ and medium‐term ozone concentration forecasting. A novel modelling technique utilizing two feed forward artificial neural networks (FFNN) is developed to improve the performance of time series predictions.

Design/methodology/approach

Air pollution and meteorological data were collected for one year in two locations in Kuwait. The hourly averages of the data were processed to generate a covariance matrix and analyzed to generate the principal component method. A two‐FFNN model is then used to predict the actual data.

Findings

The newly developed model improves the prediction accuracy over the conventional method. Owing to the presence of noise and other minor disturbances in the data, shorter‐range modelling gives better modelling results.

Originality/value

A novel modelling technique is developed to predict the time series of zone concentration.

Details

Management of Environmental Quality: An International Journal, vol. 20 no. 6
Type: Research Article
ISSN: 1477-7835

Keywords

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Article

Jo Bates, Paula Goodale, Yuwei Lin and Penny Andrews

The purpose of this paper is to adopt an assemblage theory lens to examine the socio-material forces shaping the development of an infrastructure for the recovery of…

Abstract

Purpose

The purpose of this paper is to adopt an assemblage theory lens to examine the socio-material forces shaping the development of an infrastructure for the recovery of archived historical marine weather records for use in contemporary climate data sets.

Design/methodology/approach

The authors adopted a data journeys approach to research design, conducting in-depth semi-structured interviews with climate scientists, citizen scientists and a climate historian who were engaged at key sites across the journey of data from historical record to the International Comprehensive Ocean-Atmosphere Data Set database. Interview data were complemented by further qualitative data collected via observations of working practices, a digital ethnography of citizen scientists’ online forums, and documentation relevant to the circulation and governance of climate data across emergent data infrastructures. Data were thematically analysed (Ryan and Bernard, 2003), with themes being informed primarily by the theoretical framework.

Findings

The authors identify and critically examine key points of friction in the constitution of the data recovery infrastructure and the circulation of data through it, and identify the reflexive and adaptive nature of the beliefs and practices fostered by influential actors within the assemblage in order to progress efforts to build an infrastructure despite significant challenges. The authors conclude by addressing possible limitations of some of these adaptive practices within the context of the early twenty-first century neoliberal state, and in light of current debates about data justice.

Originality/value

The paper draws upon original empirical data and a novel theoretical framework that draws together Deleuze and Guattari’s assemblage theory with key concepts from the field of critical data studies (data journeys, data friction and data assemblage) to illuminate the socio-material constitution of the data recovery infrastructure within the context of the early twenty-first century neoliberal state.

Details

Journal of Documentation, vol. 75 no. 4
Type: Research Article
ISSN: 0022-0418

Keywords

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Article

Hamza Laloui, Noor Hanita Abdul Majid and Aliyah Nur Zafirah Sanusi

This paper aims to investigate the impacts of introducing voids combinations on natural ventilation performance in high-rise residential building living unit.

Abstract

Purpose

This paper aims to investigate the impacts of introducing voids combinations on natural ventilation performance in high-rise residential building living unit.

Design/methodology/approach

This study was carried out through field measurement and computational fluid dynamics methods. The parameters of the study are void types and sizes, and a wind angle was used to formulate case studies.

Findings

The results indicate that the provision of a single-sided horizontal void larger by 50% increase the indoor air velocity performance up to 322.37% to 0.471 m/s in the living unit and achieves the required velocity for thermal comfort.

Originality/value

Passive design features are the most desirable techniques to enhance natural ventilation performance in the high-rise residential apartments for thermal comfort and indoor air quality purposes.

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Article

Kada Bouchouicha, Abdelhak Razagui, Nour El Islam Bachari and Nouar Aoun

This paper aims to propose an approach based on physical model integration for surface and cloud albedo computation using an approximate form of the atmospheric radiative…

Abstract

Purpose

This paper aims to propose an approach based on physical model integration for surface and cloud albedo computation using an approximate form of the atmospheric radiative transfer equation and sun-pixel-satellite.

Design/methodology/approach

The data used in this study are global irradiance collected from for various sites in Algeria, and data were obtained from the processing of the high-resolution visible images taken by the Meteosat Second Generation satellite in 2010.

Findings

The results suggest that the standard deviation obtained with this method is similar to that obtained with current estimation methods. The hourly and daily correlation coefficients range between 0.95 and 0.97 and between 0.97 and 0.99, respectively. The hourly and daily mean bias errors range between −0.2 and +1.2 per cent and between −0.2 and +1.4 per cent, respectively. The hourly and daily root mean square errors range between 10 and 17 per cent and between 4 and 8 per cent, respectively.

Originality/value

This paper developed a new estimating method that derives the hourly global horizontal solar irradiation at a ground level from geostationary satellite data under local climate conditions.

Details

World Journal of Engineering, vol. 13 no. 3
Type: Research Article
ISSN: 1708-5284

Keywords

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Abstract

Details

Airport Design and Operation
Type: Book
ISBN: 978-0-08-054643-8

Content available
Article

Marco Morabito, Alessandro Messeri, Alfonso Crisci, Junzhe Bao, Rui Ma, Simone Orlandini, Cunrui Huang and Tord Kjellstrom

Agricultural workers represent an important part of the population exposed to high heat-related health and productivity risks. This study aims to estimate the heat-related…

Abstract

Purpose

Agricultural workers represent an important part of the population exposed to high heat-related health and productivity risks. This study aims to estimate the heat-related productivity loss (PL) for moderate work activities in sun and shady areas and evaluating the economic cost locally in an Italian farm and generally in the whole province of Florence. Benefits deriving by working in the shade or work-time shifting were provided. Comparisons between PL estimated in Mediterranean (Florence, Italy) and subtropical (Guangzhou, China) areas were also carried out.

Design/methodology/approach

Meteorological data were collected during summers 2017–2018 through a station installed in a farm in the province of Florence and by two World Meteorological Organization (WMO)‐certified meteorological stations located at the Florence and Guangzhou airports. These data were used to calculate the wet-bulb globe temperature and to estimate the hourly PL and the economic cost during the typical working time (from 8 a.m. to 5 p.m.) and by advancing of 1 h and 2 h the working time. Significant differences were calculated through nonparametric tests.

Findings

The hourly PL and the related economic cost significantly decreased (p < 0.05) by working in the shade and by work-time shifting. Higher PL values were observed in Guangzhou than in Florence. The decrease of PL observed by work-time shifting was greater in Florence than in Guangzhou.

Originality/value

Useful information to plan suitable heat-related prevention strategies to counteract the effects of heat in the workplace are provided. These findings are essential to quantify the beneficial effects due to the implementation of specific heat-related adaptation measures to counter the impending effects of climate change.

Details

International Journal of Productivity and Performance Management, vol. 70 no. 3
Type: Research Article
ISSN: 1741-0401

Keywords

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