Max A.N. Hendriks and Jan G. Rots
The purpose of this paper is to review recent advances and current issues in the realm of sequentially linear analysis.
Abstract
Purpose
The purpose of this paper is to review recent advances and current issues in the realm of sequentially linear analysis.
Design/methodology/approach
Sequentially linear analysis is an alternative to non‐linear finite element analysis of structures when bifurcation, snap‐back or divergence problems arise. The incremental‐iterative procedure, adopted in nonlinear finite element analysis, is replaced by a sequence of scaled linear finite element analyses with decreasing secant stiffness, corresponding to local damage increments. The focus is on reinforced concrete structures, where multiple cracks initiate and compete to survive.
Findings
Compared to nonlinear smeared crack models in incremental‐iterative settings, the sequentially linear model is shown to be robust and effective in predicting localizations, crack spacing and crack width as well as brittle shear behavior. To date, sequentially linear analysis has not been devised with a proper crack closing algorithm. Besides, of utmost importance for many practical applications, sequentially linear analysis requires an improvement of the algorithm to deal with non‐proportional loadings.
Originality/value
This article gives an up‐to‐date research overview on the applicability of sequentially linear analysis. For the issue of non‐proportional loading, it indicates solution directions.
Details
Keywords
Francesco Romanò, Mario Stojanović and Hendrik C. Kuhlmann
This paper aims to derive a reduced-order model for the heat transfer across the interface between a millimetric thermocapillary liquid bridge from silicone oil and the…
Abstract
Purpose
This paper aims to derive a reduced-order model for the heat transfer across the interface between a millimetric thermocapillary liquid bridge from silicone oil and the surrounding ambient gas.
Design/methodology/approach
Numerical solutions for the two-fluid model are computed covering a wide parametric space, making a total of 2,800 numerical flow simulations. Based on the computed data, a reduced single-fluid model for the liquid phase is devised, in which the heat transfer between the liquid and the gas is modeled by Newton’s heat transfer law, albeit with a space-dependent Biot function Bi(z), instead of a constant Biot number Bi.
Findings
An explicit robust fit of Bi(z) is obtained covering the whole range of parameters considered. The single-fluid model together with the Biot function derived yields very accurate results at much lesser computational cost than the corresponding two-phase fully-coupled simulation required for the two-fluid model.
Practical implications
Using this novel Biot function approach instead of a constant Biot number, the critical Reynolds number can be predicted much more accurately within single-phase linear stability solvers.
Originality/value
The Biot function for thermocapillary liquid bridges is derived from the full multiphase problem by a robust multi-stage fit procedure. The derived Biot function reproduces very well the theoretical boundary layer scalings.
Details
Keywords
Hendrik Kohrs, Benjamin Rainer Auer and Frank Schuhmacher
In short-term forecasting of day-ahead electricity prices, incorporating intraday dependencies is vital for accurate predictions. However, it quickly leads to dimensionality…
Abstract
Purpose
In short-term forecasting of day-ahead electricity prices, incorporating intraday dependencies is vital for accurate predictions. However, it quickly leads to dimensionality problems, i.e. ill-defined models with too many parameters, which require an adequate remedy. This study addresses this issue.
Design/methodology/approach
In an application for the German/Austrian market, this study derives variable importance scores from a random forest algorithm, feeds the identified variables into a support vector machine and compares the resulting forecasting technique to other approaches (such as dynamic factor models, penalized regressions or Bayesian shrinkage) that are commonly used to resolve dimensionality problems.
Findings
This study develops full importance profiles stating which hours of which past days have the highest predictive power for specific hours in the future. Using the profile information in the forecasting setup leads to very promising results compared to the alternatives. Furthermore, the importance profiles provide a possible explanation why some forecasting methods are more accurate for certain hours of the day than others. They also help to explain why simple forecast combination schemes tend to outperform the full battery of models considered in the comprehensive comparative study.
Originality/value
With the information contained in the variable importance scores and the results of the extensive model comparison, this study essentially provides guidelines for variable and model selection in future electricity market research.
Details
Keywords
GUEST editor of this South African issue of THE LIBRARY WORLD is Hendrik M. Robinson, Director of Library Services, Transvaal Provincial Administration, Pretoria.
Paresh Wankhade, Geoffrey Heath and Peter Murphy
This chapter identifies the serious issue of the mental health and wellbeing of English paramedics working in the emergency ambulance service. It identifies the case of the extant…
Abstract
Purpose
This chapter identifies the serious issue of the mental health and wellbeing of English paramedics working in the emergency ambulance service. It identifies the case of the extant top-down performance measurement regime and the absence of indicators of wellbeing in ambulance performance reporting. The impact of such measures on frontline staff and the implications for their motivation and commitment are also documented. More decentralised, open and discursive approaches to performance management in the public sector are advocated as key methods for re-imagining ambulance and wider public services in a global context.
Design/Method
Drawing on relevant literature, the chapter provides the context of the English ambulance service and the challenges it faces with reference to the New Public Management (NPM) and New Public Governance (NPG). Key issues concerning performance metrics and staff wellbeing and welfare are then identified and discussed. The notions of communicative rationality, deliberative democracy and agonistic pluralism are introduced as a framework for analysing the state of both wellbeing and resilience and the performance regime within the English ambulance service. The chapter relates these themes to the re-imagining of public services internationally, proposing a more participative and discursive approach.
Findings
It is desirable for the evaluation of public services to include the wellbeing of the healthcare provider, as well as the public service recipient. Additionally, there is a case for greater participative and dialogic engagement to address the intertwined relationship of ambulance staff wellbeing and the performance management regime of the service. The process should be revised, therefore, to take into account the wellbeing of ambulance staff as an integral and intrinsic part of the delivery of the service, and it is recommended that deliberative methods of participation are deployed in reimagining ambulance services and public services more generally.
Originality
The challenges facing ambulance services and, more generally, health services globally continue to proliferate and intensify. They are exacerbated by foreseeable contextual challenges such as the demographic profile of patients and service users and budgetary cuts. Traditional and more recent NPM approaches are proving inadequate for this challenge and appear unsustainable in practice. The lack of acknowledgement of welfare indicators in the performance metrics make them unfit for purpose. Our suggested discursive approach would help to re-imagine the service by improving its sustainability and resilience in parallel with the improved wellbeing and personal resilience of the people who provide the service.
Details
Keywords
This chapter explores the implications of patrimonial politics in the Dutch East India Company empire in the context of establishing a settlement at the Cape of Good Hope in…
Abstract
This chapter explores the implications of patrimonial politics in the Dutch East India Company empire in the context of establishing a settlement at the Cape of Good Hope in southern Africa in the mid-seventeenth century. The Cape extended the reach of Company patrimonial networks with elite Company officials circulating throughout the Indian Ocean empire and consolidating their familial ties through marriage both within the colonies and in the United Provinces. These patrimonial networks extended to the Cape as elite Company officials created families locally or married Cape-born women. As the colony grew, the Company created a class of free-burghers some the wealthiest of whom were tied directly into elite Company patrimonial networks. But from the early eighteenth century onwards these elite Company networks came into conflict with the evolving free-burgher patrimonial networks with which they were in direct competition. This paper argues that local patrimonial networks can evolve in a settler colony that challenge the elite patrimonial networks of the imperial elite.
Details
Keywords
Wenping Xu, Wenwen Du and David G. Proverbs
This study aims to determine the key indicators affecting the resilience of the construction supply chain to flooding and calculate the resilience of the urban construction supply…
Abstract
Purpose
This study aims to determine the key indicators affecting the resilience of the construction supply chain to flooding and calculate the resilience of the urban construction supply chain in three cases city.
Design/methodology/approach
This study combines expert opinions and literature review to determine key indicators and establish a fuzzy EWM-GRA-TOPSIS evaluation model. The index weight was calculated using the entropy weight method, and GRA-TOPSIS was used for comprehensive evaluation.
Findings
The results of the study show that the three cities are ranked from the high to low in order of Hangzhou, Hefei and Zhengzhou.
Originality/value
The innovative method adopted in this study comprising EWM-GRA-TOPSIS reduced the influence of subjectivity, fully extracted and utilized data, in a way that respects objective reality. Further, this approach enabled the absolute and relative level of urban construction supply chain resilience to be identified, allowing improvements in the comprehensiveness of decision-making. The method is relatively simple, reasonable, understandable, and computationally efficient. Within the approach, the entropy weight method was used to assign different index weights, and the GRA-TOPSIS was used to rank the resilience of the construction supply chain in three urban cities. The development of resilience provides a robust decision-making basis and theoretical reference, further enriching research methods, and having strong practical value. The study serves to improve risk awareness and resilience, which in turn helps to reduce losses. It also provides enhanced awareness regarding the future enhancement of supply chain resilience for urban construction.
Details
Keywords
Francesco De Luca, Raimo Simson, Hendrik Voll and Jarek Kurnitski
Electric lighting accounts for a large share of energy consumption in commercial buildings. Utilization of daylight can significantly help to reduce the need for artificial…
Abstract
Purpose
Electric lighting accounts for a large share of energy consumption in commercial buildings. Utilization of daylight can significantly help to reduce the need for artificial lighting, increase workers productivity, customers’ satisfaction and consequently improve sales. However, excessive use of glazing and absence of lighting controls can contribute greatly to higher energy need for heating and cooling and cause undesired glare effects. Thus, optimizing the size, position and materials of external glazing, with the addition of deflectors and dynamic artificial lighting, can become key aspects in the design of sustainable low energy buildings. The purpose of this paper is to analyze daylight potential and energy performance of a hall-type commercial building, situated in the cold climate of Finland, by utilizing different combinations of skylights, windows and lighting controls.
Design/methodology/approach
The authors have used computer simulations to estimate daylight and energy performance of a single floor commercial building in relation to various combinations of skylights and windows with variable glazing materials, light deflectors and zonal lighting controls.
Findings
The results show that electric light energy saving potential ranges from a negligible 1.9 percent to a significant 58.6 percent in the case of glass skylights and wall windows using multi-zone lighting control. Total delivered energy ranges between increase of 1.5 and 21.2 percent in the cases with single zone lighting control and between decrease of 4.5 percent and increase of 4.5 percent in the cases with multi-zone control. The highest decrease in primary energy consumption was 2.2 percent for single zone and 17.6 percent for multi-zone lighting control. The research underlines the significant potential of electric light energy savings using daylighting strategies that, including the control of direct solar access for glare and internal gains, can be more than 50 percent.
Originality/value
This research combines accurate daylight and energy assessment for commercial hall buildings based in cold climate region with multiple design variations. The novelty of this work is the consideration of interior elements, shelves and deflectors, in the calculations. This is made possible through the combined use of validated simulation platforms for detailed annual daylighting and electric lighting calculation (Radiance and Daysim) and energy analysis (IDA-ICE, Equa Simulation AB). This method allows to obtain a reliable assessment of the potential of using natural light sources in buildings.
Details
Keywords
An increase in community engagement by governments across Australia’s three-tiered federal polity conforms to international trends. It represents a multidimensional…
Abstract
An increase in community engagement by governments across Australia’s three-tiered federal polity conforms to international trends. It represents a multidimensional institutionalization of participatory democracy designed to involve the public in decision-making. Increasingly, it is a practice which displays the markers of professionalization, including (self-described) professionals, professional associations and a code of ethics. The individuals who design, communicate, and facilitate community engagement are placed in a unique position, whereas most professions claim to serve both their client or employer and a greater public good, community engagement practitioners play these roles while also claiming to serve as “guardians” of democratic processes. Yet the claimed professionalization of community engagement is raising some questions: Is community engagement really a profession – and by what criteria ought this be assessed? What tensions do community engagement practitioners face by “serving multiple masters,” and how do they manage these? More pointedly, how can ethics inform our understanding of community engagement and its professionalization? This chapter examines the case for the practice of community engagement as a profession using Noordegraaf’s (2007) pillars of pure professionalism as a guide. It then explores some practical examples of the tensions practitioners may experience. The chapter concludes by reflecting on the future direction of community engagement given its positioning.