Search results

Hybrid simulation, which is a general technique for obtaining the seismic response of an entire structure, is an improvement of the traditional seismic test technique. In order to improve the analysis accuracy of the numerical substructure in hybrid simulation, the purpose of this paper is to propose an innovative hybrid simulation technique. The technique combines the multi-scale finite element (MFE) analysis method and hybrid simulation method with the objective of achieving the balance between the accuracy and efficiency for the numerical substructure simulation.

To achieve this goal, a hybrid simulation system is established based on the MTS servo control system to develop a hybrid analysis model using an MFE model. Moreover, in order to verify the efficiency of the technique, the hybrid simulation of a three-storey benchmark structure is conducted. In this simulation, a ductile column—represented by a half-scale scale specimen—is selected as the experimental element, meanwhile the rest of the frame is modelled as microscopic and macroscopic elements in the Abaqus software simultaneously. Finally, to demonstrate the stability and accuracy of the proposed technique, the seismic response of the target structure obtained via hybrid simulation using the MFE model is compared with that of the numerical simulation.

First, the use of the hybrid simulation with the MFE model yields results similar to those obtained by the fine finite element (FE) model using solid elements without adding excessive computing burden, thus advancing the application of the hybrid simulation in large complex structures. Moreover, the proposed hybrid simulation is found to be more versatile in structural seismic analysis than other techniques. Second, the hybrid simulation system developed in this paper can perform hybrid simulation with the MFE model as well as handle the integration and coupling of the experimental elements with the numerical substructure, which consists of the macro- and micro-level elements. Third, conducting the hybrid simulation by applying earthquake motion to simulate seismic structural behaviour is feasible by using Abaqus to model the numerical substructure and harmonise the boundary connections between three different scale elements.

In terms of the implementation of the hybrid simulation with the MFE model, this work is helpful to advance the hybrid simulation method in the structural experiment field. Nevertheless, there is still a need to refine and enhance the current technique, especially when the hybrid simulation is used in real complex engineering structures, having numerous micro-level elements. A large number of these elements may render the relevant hybrid simulations unattainable because the time consumed in the numeral calculations can become excessive, making the testing of the loading system almost difficult to run smoothly.

The MFE model is implemented in hybrid simulation, enabling to overcome the problems related to the testing accuracy caused by the numerical substructure simplifications using only macro-level elements.

This paper is the first to recognise the advantage of the MFE analysis method in hybrid simulation and propose an innovative hybrid simulation technique, combining the MFE analysis method with hybrid simulation method to strike a delicate balance between the accuracy and efficiency of the numerical substructure simulation in hybrid simulation. With the help of the coordinated analysis of FEs at different scales, not only the accuracy and reliability of the overall seismic analysis of the structure is improved, but the computational cost can be restrained to ensure the efficiency of hybrid simulation.

Embodied energy is the total amount of energy required to produce a product, and is significant because it occurs immediately and can be equal over the life cycle of a building to the transient requirements for operational energy. Methods for embodied energy analysis include process analysis, input‐output analysis and hybrid analysis. Proposes to improve the reliability of estimating embodied energy based on input‐output models by using an algorithm to extract systematically the most important energy paths for the “other construction” sector from an Australian input‐output model. Demonstrates the application of these energy paths to the embodied energy analysis of an individual commercial building, highlighting improvements in reliability due to the modification of energy paths with process analysis data. Compares materials and elements for the building, and estimates likely ranges of error.

The purpose of this study is to examine state-of-the-art in hybrid-electric propulsion system modeling and suggest new methodologies for sizing such advanced concepts. Many entities are involved in the modelling and design of hybrid electric aircraft; however, the highly multidisciplinary nature of the problem means that most tools focus heavily on one discipline and over simplify others to keep the analysis reasonable in scope. Correctly sizing a hybrid-electric system requires knowledge of aircraft and engine performance along with a working knowledge of electrical and energy storage systems. The difficulty is compounded by the multi-timescale dynamic nature of the problem. Furthermore, the choice of energy management in a hybrid electric system presents multiple degrees of freedom, which means the aircraft sizing problem now becomes not just a root-finding exercise, but also a constrained optimization problem.

The hybrid electric vehicle sizing problem can be sub-divided into three areas: modelling methods/fidelity, energy management and optimization technique. The literature is reviewed to find desirable characteristics and features of each area. Subsequently, a new process for sizing a new hybrid electric aircraft is proposed by synthesizing techniques from model predictive control and detailed conceptual design modelling. Elements from model predictive control and concurrent optimization are combined to formulate a new structure for the optimization of the sizing and energy management of future aircraft.

While the example optimization formulation provided is specific to a hybrid electric concept, the proposed structure is general enough to be adapted to any vehicle concept which contains multiple degrees of control freedom that can be optimized continuously throughout a mission.

The proposed technique is novel in its application of model predictive control to the conceptual design phase.

The purpose of this study is to apply hybrid cluster analysis in classifying PT Pelindo I customers based on the level of customer satisfaction with passenger services of PT Pelindo I.

Hybrid cluster analysis is a combination of hierarchical and non-hierarchical cluster analysis. This hybrid cluster analysis appears to optimize the advantages of hierarchical and non-hierarchical methods simultaneously to obtain optimal grouping. Hybrid cluster analysis itself has high flexibility because it can combine all hierarchical and non-hierarchical methods without any limits in the order of analysis used.

The results showed that 72% of PT Pelindo I customers felt PT Pelindo I service was special, while the remaining 28% felt PT Pelindo I service was good.

In total, 117 customers of PT Pelindo I were involved in a study using the non-probability sampling method.

The purpose of this paper is to present a fault tree (FT)-based approach for quantitative risk analysis in the construction industry that can take into account both objective and subjective uncertainties.

In this research, the identified basic events (BEs) are first categorized based on the availability of historical data into probabilistic and possibilistic. The probabilistic and possibilistic events are represented by probability distributions and fuzzy numbers, respectively. Hybrid uncertainty analysis is then performed through a combination of Monte Carlo simulation and fuzzy set theory. The probability of occurrence of the top event is finally calculated using the proposed FT-based hybrid uncertainty analysis method.

The efficiency of the proposed method is demonstrated by implementing in a real steel structure project. A quantitative risk assessment is performed for weld cracks, taking into account of both types of uncertainties. An importance analysis is finally performed to evaluate the contribution of each BE to the probability of occurrence of weld cracks and adopt appropriate response strategies.

In this research, the impact of objective (aleatory) dependence between the occurrences of different BEs and subjective (epistemic) dependence between estimates of the epistemically uncertain probabilities of some BEs are not considered. Moreover, there exist limitations to the application of fuzzy set rules, which were used for aggregating experts’ opinions and ranking purposes of the BEs in the FT model. These limitations can be investigated through further research.

It is believed that the proposed hybrid uncertainty analysis method presents a robust and powerful tool for quantitative risk analysis, as both types of uncertainties are taken into account appropriately.

This paper reports an investigation of a hybrid ex-state-owned enterprise (ex-SOE) providing ICT (Information and Communication Technology) services in the Italian healthcare sector (in-house provision). The authors aim to offer a framing that reflects the concerns expressed in the interdisciplinary literature on hybrid SOEs from management, public administration and, more recently, accounting.

This study operationalizes Besharov and Smith’s (2014) theoretical model on multiple logics to analyze institutional structures and organizational outcomes at an ICT in-house provider. It builds on extensive textual analysis of regulatory, archival, survey and interview data.

The study results show that the combination of hybridity in the form of layering of multiple logics in the health care sector (Polzer et al., 2016) creates problems for the effectiveness of ICT provision. In particular, the hybrid organization the authors study remained stuck in established competing relationships despite a restructure of regional health care governance. The study findings also reflect on the design of organizational control mechanisms when balancing different logics.

The identified case-study accountability practices and performance system add to the debate on hybrid organizations in the case of ex-SOEs and facilitate the understanding and management of hybrids in the public sector. The authors note policymaking implications.

The authors’ operationalization of Besharov and Smith's (2014) model adds clarity to key elements of their model, notably how to identify evidence in order to disentangle notions of centrality and compatibility. By doing this, the authors’ analysis offers potential insights into both managerial design and policy prescription. The authors provide cautionary tales around institutional reorganization regarding the layered synthesis of logics within these organizations.

Energy used in buildings is a major contributor to Australia’s energy consumption and associated environmental impacts. The advent of complex glazing systems such as double glazing, particularly in northern America and Europe, has partially closed a weak thermal link in the building envelope. In milder climates, however, building envelope features may not be as effective in life cycle energy terms, i.e. including the embodied energy of their manufacture. A net energy analysis compares the savings in operational energy to the additional requirements for embodied energy, in terms of the energy payback period and energy return on investment. The effectiveness of double glazing is determined for an Australian residential building. A wide range of building operation regimes was simulated. These results support the principle of installing double glazing in residential buildings in Melbourne, Australia, at least in terms of net primary energy savings.

This study aims to investigate the ways mobile hybrid team members make sense of their teamwork.

Using surveys, this study examined 579 US-based mobile hybrid team members as they discussed their professional team activities. Leximancer software determined, through frequency and co-occurrence analysis of survey-resulting unstructured data sets, the themes mobile hybrid team members use to make sense of their teamwork.

Participants included the concepts Team, Technology, Communication, Context and Time relative to 25 specific content themes within their talk about teamwork. While thematic clusters such as Team and Communication were densely packed, Technology and Time co-occurred more widely in support of other content themes within the mobile hybrid team member data set. This suggests mobile technologies pervade mobile hybrid team members’ sensemaking about their work.

A first of its kind inquiry into how mobile hybrid team members make sense of work and performance within their teams, this study highlights the need to explore further how mobile hybrid team members frame and enact technological processes as integral to their organizational work and team outcomes.

Fragmentation can inhibit joint goals and performance measures. Therefore, the purpose of this study is to investigate the level of fragmentation between public, private and third sectors in a hybrid organization's performance management systems and the effects of this fragmentation to propose hypotheses and new research methods for future studies.

The inductive research design was based on a mixed method approach. As empirical data, a survey, interviews and documents were used in this case study examining a hybrid organization called Welfare Alliance.

The results showed low-level fragmentation in the performance management system of the hybrid. Although the level of fragmentation was low-level, it affected the hybrid's ability to implement joint performance goals and measures. Performance management practices suffered as a consequence.

As a theoretical contribution to research addressing performance management in hybrids, the study proposes new concepts and theoretical hypotheses concerning fragmented performance management systems in hybrids. These theoretical hypotheses propose how performance goals and measures can become fragmented because they isolate service production units and activities from each other. The proposed hypotheses for future studies also attempt to provide explanations for how fragmentation can spread from one management function to another (i.e. from goal setting to performance measurement).