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Article
Publication date: 14 July 2021

Maryam Bahrami, Mehdi Khashei and Atefeh Amindoust

The purpose of this paper, because of the complexity of demand time series and the need to construct a more accurate hybrid model that can model all relationships in data…

Abstract

Purpose

The purpose of this paper, because of the complexity of demand time series and the need to construct a more accurate hybrid model that can model all relationships in data, is to propose a parallel-series hybridization of seasonal neural networks and statistical models for demand time series forecasting.

Design/methodology/approach

The main idea of proposed model is centered around combining parallel and series hybrid methodologies to use the benefit of unique advantages of both hybrid strategies as well as intelligent and classic seasonal time series models simultaneously for achieving results that are more accurate for the first time. In the proposed model, in contrast of traditional parallel and series hybrid strategies, it can be generally shown that the performance of the proposed model will not be worse than components.

Findings

Empirical results of forecasting two well-known seasonal time series data sets, including the total production value of the Taiwan machinery industry and the sales volume of soft drinks, indicate that the proposed model can effectively improve the forecasting accuracy achieved by either of their components used in isolation. In addition, the proposed model can achieve more accurate results than parallel and series hybrid model with same components. Therefore, the proposed model can be used as an appropriate alternative model for seasonal time series forecasting, especially when higher forecasting accuracy is needed.

Originality/value

To the best of the authors’ knowledge, the proposed model, for first time and in contrast of traditional parallel and series hybrid strategies, is developed.

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Article
Publication date: 28 July 2021

Navin Kumar, R.S. Walia and Surjit Angra

The aim of the present study is to find the tribological properties of newly developed polyester-based hybrid glass-jute fibre reinforced plastic composites loaded with…

Abstract

Purpose

The aim of the present study is to find the tribological properties of newly developed polyester-based hybrid glass-jute fibre reinforced plastic composites loaded with different weight per cent of hybrid filler particles were investigated under a dry sliding medium from room temperature to 75°C.

Design/methodology/approach

The study was carried out using a pin-on-disc wear test set-up. The design of experiments was carried out in a controlled way using a central composite design based on response surface methodology to observe the effect of various parameters i.e. sliding velocity, sliding distance, the temperature of counterface and different applied load conditions during dry-sliding.

Findings

The maximum wear resistance was found at 9 Wt% loading of filler, 4 ms-1 sliding velocity, 30 N applied load, 54°C temperature of the counterface and 1,100 m sliding distance condition. Optimum values of hybrid filler loading, sliding velocity, applied load, the temperature of the counterface and sliding distance for the minimum coefficient of friction value and minimum friction force are 9 Wt%, 4 ms−1, 30 N, 54° C, 1,100 m and 12 Wt%, 3 ms−1, 20 N, 59°C and 1,100 m, respectively. The worn surface morphology was studied using scanning electron microscope, for wear dominant mechanisms.

Originality/value

The tribological properties of newly developed polyester-based hybrid glass-jute fibre reinforced plastic composites loaded with different weight % of hybrid filler particles, were investigated under dry sliding medium from room temperature to 75°C has not been attempted yet.

Details

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

Keywords

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Article
Publication date: 18 June 2021

Gustaf Kastberg Weichselberger and Cristian Lagström

The authors argue that the mainstream scholarly discourse on hybridity and accounting is thus far primarily interested in the use and effects of accounting “in” hybrid

Abstract

Purpose

The authors argue that the mainstream scholarly discourse on hybridity and accounting is thus far primarily interested in the use and effects of accounting “in” hybrid organizations. Consequently, the literature has to a lesser extent explored how accounting mediates hybrid settings (while also being mediated), and the role of disentanglements in such processes. In hybrid settings, objects are difficult to define, and measures and tools difficult to agree upon. However, the literature on hybrid accounting is inconclusive and indicates that accounting can potentially both stabilize and de-stabilize relations in a hybrid setting. The authors address the research question of how accounting emerges and manifests itself in a process of entangling and disentangling in a heterogeneous emerging hybrid setting.

Design/methodology/approach

The paper is based on a longitudinal qualitative case study of the implementation of social investments, a public sector calculative framework based on the logic of measuring long term and social and economic impact of prevention. Methodologically, the study was guided by actor-network theory. In total, 18 observations and 48 interviews were conducted.

Findings

The observation the authors make in their case study is that much effort was spent on both keeping things apart and tying elements together. What the authors add to the literature is an illumination of how the interplay between entanglements and disentanglements facilitated the design idea of social investments to be enacted as multiple semi-integrated and purified hybridizations. The authors describe different translation points, each representing a specific hybridization where elements were added, recombined and disentangled. Still, the translation points were not completely compartmentalized, but rather semi-integrated where associations were facilitated through active mediation, likeness and productiveness for each other.

Research limitations/implications

One limitation is the single case approach. A second limitation arises from the ANT approach to hybridity.

Practical implications

A practical implication of this paper is that in hybrid settings, the semi-integrated character may be interpreted as a strength because it allows the mobilization of heterogenous actors. However, this may also come at the cost of governability and raises further questions of managerial practices in hybrid settings.

Social implications

The paper suggests the potentially productive role of disentanglements in allowing multiple hybridizations to evolve in hybrid accounting settings.

Originality/value

The paper suggests the potentially productive role of disentanglements in allowing multiple stabilized hybridizations to evolve in hybrid accounting settings.

Details

Accounting, Auditing & Accountability Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0951-3574

Keywords

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Article
Publication date: 24 June 2021

Anne Stafford and Pamela Stapleton

Contemporary organisational landscapes offer opportunities for hybrids to thrive. Public–private partnerships (PPPs) are one thriving hybrid form incorporating the use of…

Abstract

Purpose

Contemporary organisational landscapes offer opportunities for hybrids to thrive. Public–private partnerships (PPPs) are one thriving hybrid form incorporating the use of resources and/or structures from both public and private sectors. The study examines the impact of such a hybrid structure on governance and accountability mechanisms in a context of institutional complexity.

Design/methodology/approach

This study uses an approach that draws on institutional logics and hybridity to examine governance arrangements in the PPP policy created for the delivery of UK schools. Unusually, it employs a comparative case study of how four local governments implemented the policy. It draws on a framework developed by Polzer et al. (2017) to examine the level of engagement between multiple logics and hybrid structures and applies this to the delivery of governance and accountability for public money.

Findings

The Polzer et al. framework enables a study of how the nature of hybrids can vary in terms of their governance, ownership and control relations. The findings show how the relationships between levels of engagement of multiple logics and hybrid structures can impact on governance and accountability for public money. Layering and blending combinations led to increased adoption of private sector accountability structures, whilst a hybrid with parallel co-existence of community and market logics delivered a long-term governance structure.

Research limitations/implications

The paper examines the operation of hybrids in a complex education PPP environment in only four local governments and therefore cannot provide representative answers across the population as a whole. However, given the considerable variation found across the four examples, the paper shows there can be significant differentiation in how multiple logics engage at different levels and in varying combinations even in the same hybrid setting. The paper focuses on capital investment implementation and its evaluation, so it is a limitation that the operational stage of PPP projects is not studied.

Practical implications

The findings have political relevance because the two local government bodies with more robust combinations of multiple logics were more successful in getting funds and delivering schools in their geographical areas.

Originality/value

The study extends Polzer et al.'s (2017) research on hybridity by showing that there can be significant differentiation in how multiple logics engage at different levels and in varying combinations even in what was planned to be the same hybrid setting. It shows how in situations of institutional complexity certain combinations of logics lead to differentiation in governance and accountability, creating fragmented focus on the related public accountability structures. This matters because it becomes harder to hold government to account for public spending.

Details

Accounting, Auditing & Accountability Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0951-3574

Keywords

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Article
Publication date: 9 July 2021

Hosein Taghaddos, Mohammad Hosein Heydari and AmirHosein Asgari

This study aims to propose a hybrid simulation approach for site layout and material laydown planning in construction projects considering both the project’s continuous…

Abstract

Purpose

This study aims to propose a hybrid simulation approach for site layout and material laydown planning in construction projects considering both the project’s continuous and discrete state.

Design/methodology/approach

Efficient site layout planning (SLP) is a critical task at the early stages of the project to enhance constructability and reduce safety risks, construction duration and cost. In this paper, external and internal conditions affecting SLP gets identified. Then dynamic features of project conditions and project operations are analyzed by using a hybrid simulation approach combining continuous simulation (CS) and discrete event simulation (DES).

Findings

An efficient site layout plan regarding the project conditions results in cost efficiency. Instead of using DES or CS alone, this paper uses a hybrid simulation approach. Such a hybrid method leads to more accurate results that enable construction managers to make better decisions, such as material management variables. The proposed approach is implemented in a real construction project (i.e. earthmoving operation) to evaluate the hybrid simulation approach’s performance.

Practical implications

The proposed approach is implemented in a real construction project (i.e. earthmoving operation) to evaluate the performance of the hybrid simulation approach.

Originality/value

Although DES is used widely in construction simulation, it involves some limitations or inefficiencies. On the other hand, modeling resource interactions and capturing the construction project’s holistic nature with CS or system dynamics face some challenges. This study uses a hybrid DES and CS approach to enhance commercial construction projects’ SLP.

Content available
Article
Publication date: 22 June 2021

Joshua Maine, Emilia Florin Samuelsson and Timur Uman

Drawing on paradox theory, this study explores how ambidextrous sustainability relates to organisational performance in hybrid organisations represented by Swedish…

Abstract

Purpose

Drawing on paradox theory, this study explores how ambidextrous sustainability relates to organisational performance in hybrid organisations represented by Swedish municipal housing corporations, and how this relationship is contingent on the organisational structure of these organisations.

Design/methodology/approach

The study relies on the data collected from Swedish municipal housing corporations. These data sources consist of a survey sent to the management team members in Swedish municipal housing corporations, financial and non-financial archival data on these corporations, interviews with the management team and board members, and observations of meetings involving the management team and board of directors at a Swedish municipal housing corporation. Quantitative data of the study were analysed using descriptive statistics, correlation analysis and linear multiple regression analysis. Qualitative data were analysed employing deductive thematic analysis and were used to illustrate and discuss the results of the quantitative analysis.

Findings

The quantitative findings show that ambidextrous sustainability, i.e. the alignment between an explorative orientation and an exploitative orientation towards sustainability, has a weakly positive relationship with financial performance and a positive relationship with social performance in hybrid organisations represented by Swedish municipal housing corporations. The study further shows that a high level of the structural element “connectedness” weakened the relationship between the ambidextrous sustainability and financial performance of the organisation in the study. In contrast, a lower level of connectedness reinforced and strengthened this relationship. Our qualitative material illustrates how the quantitative findings could be explained by the interaction between the board of directors and the management team of these hybrid organisations.

Originality/value

The study shows how ambidextrous sustainability, employed for conceptualisation of the sustainability strategy in hybrid organisations, represented by Swedish municipal housing corporations, can impact on facets of performance (i.e. financial, social and environmental) differently. The study further highlights the importance of organisational structures in these relationships in a hybrid context.

Details

Accounting, Auditing & Accountability Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0951-3574

Keywords

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Article
Publication date: 19 June 2021

Sathiyamoorthy Margabandu and Senthil Kumar Subramaniam

The study aims to investigate the influence of fabric hybridization, stacking sequences and matrix materials on the tensile strength and damping behavior of jute/carbon…

Abstract

Purpose

The study aims to investigate the influence of fabric hybridization, stacking sequences and matrix materials on the tensile strength and damping behavior of jute/carbon reinforced hybrid composites.

Design/methodology/approach

The hybrid composites were fabricated with different sequences of fabric plies in epoxy and polyester matrix using a hand layup technique. The tensile and vibration characteristics were evaluated on the hybrid laminated composite models using finite element analysis (FEA), and the results were validated experimentally according to ASTM standards. The surface morphology of the fractured specimens was studied using the scanning electron microscope.

Findings

The experimental results revealed that the position of jute layers in the hybrid composites has a significant influence on the tensile strength and damping behavior. The hybrid composite with jute fiber at the surface sides and carbon fibers at the middle exhibited higher tensile strength with superior damping properties. Further, it is found that the experimental results are in good coherence with the FEA results.

Originality/value

The less weight and low-cost hybrid composites were fabricated by incorporating the jute and carbon fabrics in interply configurations. The influences of fabric hybridization, stacking arrangements and matrix materials on the tensile and vibration behavior of jute/carbon hybrid composites have been numerically evaluated and the results were experimentally validated.

Details

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

Keywords

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Article
Publication date: 19 June 2009

J. Sharana Basavaraja, Sathish Sharma and Sathish Jain

The non‐recessed hybrid journal bearings of cylindrical type, when operating at higher rotational speeds can suffer self‐exited vibrations(oil‐whirl Instability), which…

Abstract

Purpose

The non‐recessed hybrid journal bearings of cylindrical type, when operating at higher rotational speeds can suffer self‐exited vibrations(oil‐whirl Instability), which can cause excessive rotor motion causing bearing and sometimes total machine failure. The multi‐lobe journal bearing exhibits better stability as well as a superior capability to suppress oil‐whirl. The paper aims to present a theoretical study pertaining to a two‐lobe hole‐entry hybrid journal bearing by considering the combined influence of surface roughness and journal misalignment on the performance of the bearing.

Design/methodology/approach

The average Reynolds equation governing the flow of lubricant in the clearance space between the rough bearing surfaces together with the equation of flow through a capillary restrictor has been solved using FEM. The bearing performance characteristics have been simulated for a two‐lobe hole‐entry hybrid journal bearing for the various values of offset factor, restrictor design parameter, surface roughness parameter, surface pattern parameter and journal misalignment parameters.

Findings

The two‐lobe hole‐entry hybrid journal bearing system with an offset factor greater than one indicates significant improvement of the order of 15‐25 percent in the values of direct stiffness and direct damping coefficients compared to a circular hole‐entry hybrid journal bearing system. Also the lubricant flow of a two‐lobe hole‐entry hybrid journal bearing is reduced by 25 percent vis‐à‐vis circular bearing.

Originality/value

The present work is original of its kind, in case of two‐lobe hole‐entry hybrid journal bearing. The results are quite useful for the bearing designer.

Details

Industrial Lubrication and Tribology, vol. 61 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 30 September 2014

C. Pornet, S. Kaiser, A.T. Isikveren and M. Hornung

The aim of this paper is to assess the potential of fuel-battery hybrid narrow-body (180PAX) transport aircraft according to different design ranges for an…

Abstract

Purpose

The aim of this paper is to assess the potential of fuel-battery hybrid narrow-body (180PAX) transport aircraft according to different design ranges for an entry-into-service (EIS) of 2035.

Design/methodology/approach

The philosophy used in the design of the twin-engine fuel-battery hybrid concept is to use the power of an electric motor during cruise to drive a single propulsive device, whereas the other one is powered conventionally by an advanced gas turbine. A methodology for the sizing and performance assessment of hybrid energy aircraft was previously proposed by the authors. Based on this methodology, the overall sizing effects at aircraft level are considered to size the hybrid aircraft to different range applications. To evaluate the hybrid concept, performance was contrasted against a conventional aircraft projected to EIS 2035 and sized for identical requirements. Additionally, sensitivity of the prospects against different battery technology states was analysed.

Findings

The best suited aircraft market for the application of the fuel-battery hybrid transport aircraft concept considered is the regional segment. Under the assumption of a battery-specific energy of 1.5 kWh/kg, block fuel reduction up to 20 per cent could be achieved concurrently with a gate-to-gate neutral energy consumption compared to an advanced gas-turbine aircraft. However, a large increase in maximum take-off weight (MTOW) occurs resulting from battery weight, the additional electrical system weight, and the cascading sizing effects. It strongly counteracts the benefit of the hybrid-electric propulsion technology used in this concept for lower battery-specific energy and for longer design ranges.

Practical implications

The findings will contribute to the evaluation of the feasibility and impact of hybrid energy transport aircraft as potential key enablers of the European and US aeronautical program goals towards 2035.

Originality/value

The paper draws its value from the consideration of the overall sizing effects at aircraft level and in particular the impact of the hybrid-electric propulsion system to investigate the prospects of fuel-battery hybrid narrow-body transport aircraft sized at different design ranges.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 86 no. 6
Type: Research Article
ISSN: 0002-2667

Keywords

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Article
Publication date: 1 January 1989

N. Sinnadurai

In order to identify and quantify the size and shape of the rapidly changing complexion of the market for hybrid microelectronics, in 1987 ISHM launched a survey in Europe…

Abstract

In order to identify and quantify the size and shape of the rapidly changing complexion of the market for hybrid microelectronics, in 1987 ISHM launched a survey in Europe of the market for thin‐film, thick‐film and surface‐mount‐on‐PCB hybrids for the periods 1980, 1986 and 1990. The survey aimed to obtain a hierarchical breakdown of the markets also into technology and application sectors. The general findings are reported. The credibility and quantity of the survey are considered in the context of the market for electronic equipment in Europe for 1987 and 1990. In electronics there is a continuing pressure to reduce prices and therefore adjustments should not be made for inflation. A growth in market value is thus a true reflection of a larger growth in market volume and a continuing increase in complexity. Thus, the 11% CAGR for 1986–1990 reflects a growth in equipment volumes of 20% over the 4 year period. Manufacturers will have to design and build increasingly complex circuits at a higher throughput and lower cost, at an increasing pace. It is not a business for faint hearts. Clearly the growth potential for the hybrid microelectronics market should be considered in the context of the equipment market, in order to judge the relative growth. In order to distinguish between the hybrid and PCB industries, the survey has aimed to estimate the growth in the developing market for hybrids using substrates up to 6 in. × 4 in. (Eurocard), not including the larger SMAs on PCBs for which there is a huge market growth potential. The immediate opportunity is from miniaturisation and cost reduction using hybrid microelectronics. The major push in technological emphasis in modern hybrids comes from the need for high‐density interconnection to support increasingly complex VLSI in high‐pin‐count surface‐mount micropackages and high‐performance substrates to support VHSIC and high‐performance circuits. Hence there is a major shift in hybrid microelectronics technology emphasis towards high‐density surface‐mount assemblies on PCB and other organic substrates. The total hybrid market sub‐divided among the basic three technologies reveals this emphasis. The portents are clear, and those who intend to succeed, or even simply survive, need to be aware of the shift in emphasis and prepare to diversify or establish strengths in niche applications.

Details

Microelectronics International, vol. 6 no. 1
Type: Research Article
ISSN: 1356-5362

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