Wireless sensor networks have become incredibly popular due to the Internet of Things' (IoT) rapid development. IoT routing is the basis for the efficient operation of the perception-layer network. As a popular type of machine learning, reinforcement learning techniques have gained significant attention due to their successful application in the field of network communication. In the traditional Routing Protocol for lowpower and Lossy Networks (RPL) protocol, to solve the fairness of control message transmission between IoT terminals, a fair broadcast suppression mechanism, or Drizzle algorithm, is usually used, but the Drizzle algorithm cannot allocate priority. Moreover, the Drizzle algorithm keeps changing its redundant constant k value but never converges to the optimal value of k. To address this problem, this paper uses a combination based on reinforcement learning (RL) and trickle timer. This paper proposes an RL Intelligent Adaptive Trickle-Timer Algorithm (RLATT) for routing optimization of the IoT awareness layer. RLATT has triple-optimized the trickle timer algorithm. To verify the algorithm's effectiveness, the simulation is carried out on Contiki operating system and compared with the standard trickling timer and Drizzle algorithm. Experiments show that the proposed algorithm performs better in terms of packet delivery ratio (PDR), power consumption, network convergence time, and total control cost ratio.

Purpose – The contribution of lean construction techniques in sustainable construction cannot be over emphasised, as sustainable development is now enshrined in government policy. In addition, lean construction is now faced with the challenges of sustainable development, continuous improvement, waste elimination, a stronger user focus, increased value for money along with high quality management of projects and supply chains, and improved communications. This paper presents an exploratory study from extant literature and the results of the use of questionnaire survey among construction participants to explore the contribution of implementing lean construction techniques in sustainable construction. Design/methodology/approach – Surveys of UK-based construction professional were conducted. The data collected were analysed with SPSS 19.0 version software using the percentile method, Cronbach ' s α reliability test, Kruskal Wallis test, Kendall ' s coefficient of concordance and one sample t-test. Findings – Results from this study indicate that there are several benefits associated with implementation of lean construction and sustainable construction. The overall perspective of professionals within the construction industry, according to questionnaire survey, shows that benefits such as improved corporate image and sustainable competitive advantage, improved process flow and productivity, improvement in environmental quality and increased compliance with customer ' s expectations are realised following integration of principles of lean construction and sustainable construction within construction industry. Just-in-time, visualisation tool, value analysis, daily huddle meetings and value stream mapping are the most common lean tools/techniques for enabling sustainability. This study also identified several areas of linkage between lean and sustainability such as waste reduction, environmental management, value maximisation, and health and safety improvement among others. Originality/value – The originality of this paper lies in its consideration of lean construction principles to better understand its impact on sustainable construction. This research contributes to the awareness of the benefits that can be derived from the implementation of lean construction in sustainable construction within the construction industry.

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Citation: Sutrisna, Monty and Goulding, Jack (2019) Managing information flow and design processes to reduce design risks in offsite construction projects. Engineering, Construction and Architectural Management, 26 (2). This document may differ from the final, published version of the research and has been made available online in accordance with publisher policies. To read and/or cite from the published version of the research, please visit the publisher's website (a subscription may be required.) Managing information flow and design processes to reduce design risks in offsite construction projectsAbstract Purpose: Following the increasing need for faster construction, improved quality, and evidence value propositions, offsite construction is increasingly being proffered as a viable contender to 'traditional' construction approaches. However, whilst evidence supports the move towards offsite, its uptake has been lower than expected. Whilst the precise reasons for this seem to be influenced by a number of issues, including contextual drivers and market maturity; some project stakeholders also view offsite as carrying greater risks. This paper reports on the quality of information flow, in particular, the impact and influence of this on design risks in offsite construction projects.Design/methodology: An existing design risk framework is used as the point of departure for this research. This is further expanded into a specific model for evaluating offsite construction projects design risks, the rubrics of which were informed by two case studies of offsite construction projects in Australia and the UK analysed with a process-tracing technique. Whilst these cases were geographically separated, the constructs were aligned to uncover fundamental design information requirements and concomitant risks associated with offsite.Findings: The findings of the research reported in this paper include the crucial information feeding into the design process emanating from the lifecycle of offsite construction projects, namely design, offsite (manufacturing), handling and transporting, site works and installation and also occupancy. These are contextualised within the four categories, namely client requirements, project requirements, regulation aspects and social aspects and the final outcomes were summarised into a holistic diagram.Originality/value: Given that the offsite construction has shifted the working paradigm into assigning a significant level of efforts and emphasis at the front end of the construction projects, the importance of its design process and hence design risks management has gone up significantly in construction projects delivered using this technique. This research and paper contributes significantly to the built environment domain by identifying the crucial aspects along the project lifecycle to be considered to minimise the potential occurrence of design risks and hence increasing the confidence of project stakeholders in adopting offsite construction techniques in their projects.

PurposeThe purpose of this paper is to report on findings from the first stage of an ongoing research with regard to the UK construction industry's perception of offsite production (OSP) adoption/uptake, in an attempt to inform the second stage of the research (not reported in this paper) to infer the skills/knowledge areas needed for the wider uptake of OSP.Design/methodology/approachThe objective of this paper was to capture the UK construction industry's perception vis‐à‐vis OSP characteristics using a quantitative approach. Postal surveys were employed to collect industry perception which was then analysed statistically for inference and conclusion.FindingsFindings from 36 large construction organisations suggest that irrespective of respondents' organisations prime activity or professions, the majority of respondents perceive OSP to be the future of the UK construction industry; with a considerable belief that the industry is ready to embrace OSP. Nevertheless, the industry do not seem to fully appreciate OSP, which is implied by the uncertainty recorded in most of the responses.Research limitations/implicationsWhilst the data validity and sample set coherence can be considered robust and defendable, it should be acknowledged that care needs to be taken when interpreting results, especially as the data collected depended heavily on the survey approach. Furthermore, these findings are limited to the UK context only, as such, the level of generalisability/repeatability outside this context may not be representative of the findings presented here.Originality/valueOSP falls under the overarching umbrella of modern methods of construction, which is high on the UK Government Agenda. OSP has attracted numerous research over the last decades; however, there is limited literature to quantify industry perception in this regard, especially to enable the inference and prioritisation of skills and knowledge areas needed to support the wider uptake of OSP (not reported in this paper).