Ajith Kumar Parlikad

Ajith Kumar Parlikad
University of Cambridge | Cam ·  Institute for Manufacturing

PhD

About

246
Publications
109,951
Reads
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2,539
Citations
Introduction
Dr Ajith Kumar Parlikad is Professor of Asset Management at Cambridge University Engineering Department. He is the Head of the Asset Management Research Group and a co-investigator of the Centres for Smart Infrastructure and Construction, and Digital Built Britain. His research has been funded by the EPSRC, Innovate UK, EU H2020 and industry. His current research focusses on exploiting data and digital technologies to improve predictive asset management.
Additional affiliations
January 2007 - present
University of Cambridge
Position
  • Lecturer
Education
October 2002 - August 2006
University of Cambridge
Field of study
  • Manufacturing and Management

Publications

Publications (246)
Article
Full-text available
When failure data are limited, data-driven prognostics solutions underperform since the number of failure data samples is insufficient for training prognostics models effectively. In order to address this problem, we present a novel methodology for generating failure data which allows training datasets to be augmented so that the number of failure...
Article
Full-text available
Anomaly detection in asset condition data is critical for reliable industrial asset operations. But statistical anomaly classifiers require certain amount of normal operations training data before acceptable accuracy can be achieved. The necessary training data are often not available in the early periods of assets operations. This problem is addre...
Article
Full-text available
This paper proposes a framework to analyse traffic-data processes on a long-haul backbone infrastructure network providing internet services at a national level. This type of network requires low latency and fast speed, which means there is a large demand for research focusing on near real-time decision-making and resilience assessment. To this aim...
Article
Full-text available
Scour is one of the main causes of bridge failures resulting in significant macroeconomic impacts, often beyond the direct costs of infrastructure damage. Given the pressure to increase the resilience of transport networks, ageing bridge infrastructure, constrained budgets, variable knowledge of asset conditions and limited data, mixed ownership an...
Article
Despite increasing interest, real-time prognostics (failure prediction) is still not widespread in industry due to the di fficulties of existing systems to adapt to the dynamic and heterogeneous properties of real asset fleets. In order to address this, we present an Industrial Multi Agent System for real-time distributed collaborative prognostics....
Chapter
Modelling the times-to-failures in industrial assets is critical for their maintenance planning. Modern fleets often comprise of clusters of similarly deteriorating assets, due to customisation or diversity in their operational settings. As such, the prevalent techniques of using a single fleet-wide model or independent cluster-specific models for...
Conference Paper
Smart manufacturing uses data-driven solutions to improve performance and operations resilience, requiring large amounts of data delivered quickly, enabled by telecom networks. Disruptions can shut down a network; avoiding them needs responsiveness to network usage, achievable by embedding autonomy into the network with fast and scalable algorithms...
Article
Full-text available
Autonomic computing investigates how systems can achieve (user) specified “control” outcomes on their own, without the intervention of a human operator. Autonomic computing fundamentals have been substantially influenced by those of control theory for closed and open-loop systems. In practice, complex systems may exhibit a number of concurrent and...
Article
A population‐level analysis is proposed to address data sparsity when building predictive models for engineering infrastructure. Utilizing an interpretable hierarchical Bayesian approach and operational fleet data, domain expertise is naturally encoded (and appropriately shared) between different subgroups, representing (1) use‐type, (2) component,...
Conference Paper
Full-text available
The realisation of a fast and resilient communication network is a must in the society today, with a large number of infrastructure, business and end-users connected to the internet. This work proposes a definition and evaluation of the internet infrastructure criticality at the long-haul, physical level, of the backbone network. The approach is do...
Article
Full-text available
The physical assets within a critical infrastructure system is pivotal to its efficient performance and protection and that of other dependent systems. This is particularly the case for the communication systems where network protection strategies usually involve asset redundancy. Although such a redundancy is well modelled in the literature, there...
Conference Paper
Infrastructure systems in today's increasingly interconnected world employ the capabilities of the Internet of Things (IoT) technologies for their monitoring, operational control, and asset management. IoT devices can be defined as sensors (of different types) collecting, processing, and sharing time series of data. The analysis of such data often...
Conference Paper
The ports sector is critical to global trade. While digitalisation of infrastructure asset management in other sectors such as manufacturing, healthcare, water supply, railway and road is rapidly growing with the possibilities of the Internet of Things (IoT) solutions, the maritime industry lags significantly behind. IoT solutions and the near real...
Conference Paper
Full-text available
Bridges are strategic connection points within the transport network, underpinning economic vitality, social-wellbeing, and logistics of communities. Currently, most of the transport authorities are not able to identify bridges at higher risk of disruptions, due to limited data or lack of a risk-informed assessment, and this is particularly true fo...
Conference Paper
Full-text available
The emergence of the digital twin concept can potentially change the way people manage built assets thoroughly. This is because the semantics-based model and linked data approach behind the digital twin, as the successor of classical BIM, provide strong capability in integrating data from fragmented and heterogeneous sources and thus enables better...
Conference Paper
Full-text available
The digital twin concept emerged recently in the Architecture, Engineering, Constructions and Operations domain and the interest for digital built asset management service implementations is increasing. However, most of the applications are developed according to custom approaches, preventing the generalisation and modularisation. This article pres...
Article
Full-text available
The role of urban infrastructure is becoming increasingly interdependent, resulting in new sources of vulnerability. Infrastructural asset failure can propagate between rail transportation and other infrastructure networks. There remains a lack of academic research focusing on the dynamic simulation of city-wide infrastructure using real-life data...
Article
Full-text available
Numerous bridges are exposed to increasingly frequent and intense extreme events due to climate change, while serving more traffic than originally designed due to population growth. Thus, predictive maintenance of bridges is of paramount importance for securing structural safety and bridge network reliability. However, the application of predictive...
Article
Full-text available
Smart manufacturing uses advanced data-driven solutions to improve performance and operations resilience requiring large amounts of data delivered quickly, enabled by telecom networks and network elements such as routers or switches. Disruptions can render a network inoperable; avoiding them requires advanced responsiveness to network usage, achiev...
Preprint
Full-text available
We propose a population-level analysis to address issues of data sparsity when building predictive models of engineering infrastructure. By sharing information between similar assets, hierarchical Bayesian modelling is used to improve the survival analysis of a truck fleet (hazard curves) and power prediction in a wind farm (power curves). In each...
Conference Paper
Smart manufacturing uses advanced data-driven solutions to improve performance and operations resilience requiring large amounts of data delivered quickly, enabled by telecom networks and network elements such as routers or switches. Disruptions can render a network inoperable; avoiding them requires advanced responsiveness to network usage, achiev...
Preprint
Full-text available
Autonomic computing investigates how systems can achieve (user) specified control outcomes on their own, without the intervention of a human operator. Autonomic computing fundamentals have been substantially influenced by those of control theory for closed and open-loop systems. In practice, complex systems may exhibit a number of concurrent and in...
Article
Full-text available
Understanding SARS-CoV-2 transmission in higher education settings is important to limit spread between students, and into at-risk populations. In this study, we sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding c...
Article
Full-text available
Understanding SARS-CoV-2 transmission in higher education settings is important to limit spread between students, and into at-risk populations. In this study, we sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding c...
Article
Previous researchers have made impressive strides in developing algorithms and solution methodologies to address multi-objective optimization (MOO) problems in industrial engineering and associated fields. One traditional approach is to determine a Pareto optimal set that represents the trade-off between objectives. However, this approach could res...
Article
Full-text available
Systems engineering crosses multiple engineering disciplines for the design, control, and overall management of engineered systems. Such systems can be classified into chemical, civil, management, electrical, mechanical, and geotechnical areas. All these systems have an intrinsic complexity such that their analysis and synthesis should be addressed...
Conference Paper
Full-text available
Building energy conservation is among the most cost-efficient paths to achieve sustainability. An in-depth understanding of the energy consumed during the operation guides more effective energy-saving actions. With the adoption of submetering systems, fine-grained building energy analysis is enabled. This allows characterising the dynamics underlyi...
Article
Full-text available
Planning transport infrastructure development involves high levels of uncertainty due to socioeconomic , environmental and technological changes. Methodologies currently used in transport planning often have minimal consideration for adaptiveness, leading to costly redesigns or cancellation of entire projects. Presented herein is the investigation...
Conference Paper
Full-text available
While the benefits of monitoring bridges are fairly understood, securing the resources necessary for their development and installation is often difficult. The premise of the article is that infrastructure owners will take action to provide those resources when they can see value accruing to them; therefore narratives around value generation and bu...
Article
There is an increasing interest in the reliability of complex engineering systems, especially in the systems’ through-life risk analysis. A complex system, like the civil aircraft engine studied in this paper, contains multiple potential failure modes throughout its life that are contributed by various sub-system and component failures going throug...
Conference Paper
The Digital Twin (DT) concept is increasingly employed as a powerful tool to support datadriven decision making in management of the built environment. Various open Data Models (DM), addressing specific scale and domain applications, can be found in the literature. However, many DT implementations are based on organisation-specific information mana...
Conference Paper
Full-text available
State of the art research in ensuring transport infrastructure resilience focuses on adopting a network perspective. However, there is no comprehensive, widespread method for evaluating connectivity and proposing alternative routes to improve it. Presented herein is a framework that: assesses road network connectivity, using a "closeness" measure a...
Article
Full-text available
Various maturity models have been developed for understanding the diffusion and implementation of new technologies/approaches. However, we find that existing maturity models fail to understand the implementation of emerging digital twin technique comprehensively and quantitatively. This research aims to develop an innovative maturity model for meas...
Article
Full-text available
Studying the influence of imperfect prognostics information on maintenance decisions is an underexplored area. To bridge this gap, a new comprehensive maintenance support system is proposed. First, a survival theory-based prognostics module employing the Weibull time-to-event recurrent neural network was deployed in which prognostics competence was...
Article
Full-text available
COVID-19 has disrupted healthcare operations and resulted in large-scale cancellations of elective surgery. Hospitals throughout the world made life-altering resource allocation decisions and prioritised the care of COVID-19 patients. Without effective models to evaluate resource allocation strategies encompassing COVID-19 and non-COVID-19 care, ho...
Preprint
Full-text available
Transmission of SARS-CoV-2 without symptoms is well described, and may be mitigated by mass testing. Nonetheless, the optimal implementation and quantitative real-world impact of this approach remain unclear. During a period of rising SARS-CoV-2 prevalence, students at the University of Cambridge were enrolled in a voluntary programme of weekly PCR...
Article
Budget allocation problems in portfolio management are inherently multi-objective as they entail different types of assets of which performance metrics are not directly comparable. Existing asset management methods that either consolidate multiple goals to form a single objective (a priori) or populate a Pareto optimal set (a posteriori) may not be...
Chapter
Full-text available
Telecommunication networks are designed to route data along fixed pathways, and so have minimal reactivity to emergent loads. To service today’s increased data requirements, networks management must be revolutionised so as to proactively respond to anomalies quickly and efficiently. To equip the network with resilience, a distributed design calls f...
Article
The emergence of COVID-19 pandemic is causing tremendous impact on our daily lives, including the way people interact with buildings. Leveraging the advances in machine learning and other supporting digital technologies, recent attempts have been sought to establish exciting smart building applications that facilitates better facility management an...
Article
Full-text available
Agent-based systems have been widely used to develop industrial control systems when they are required to address issues such as flexibility, scalability and portability. The most common approach to develop such control systems is with agents embedded in a platform that provides software libraries and runtime services that ease the development proc...
Article
The assets in Industry 4.0 are categorised into physical, virtual and human. The innovation and popularisation of ubiquitous computing enhance the usage of smart devices: RFID tags, QR codes, LoRa tags, etc. for assets identification and tracking. The generated data from Industrial Internet of Things (IIoT) eases information visibility and process...
Article
Full-text available
In this paper, we present a risk evaluation and maintenance strategy optimization approach for systems with parallel identical assets subject to continuous deterioration. System performance is defined by the number of functional assets, and the penalty cost is measured by the loss of performance. To overcome the practical challenges of information...
Chapter
Full-text available
Most of the existing research on BIM implementation and benefits realisation has departed from a technocentric perspective and instead promoted the belief that the benefits of using BIM technologies are an inevitable outcome of adoption in and of itself. Recently, scholars have acknowledged that important links between implementation practices and...
Article
During the operation of airplanes in the aviation industry, the stochastic environment in which the airplanes are being operated creates high complexity in planning the fleet overhauls for the aircraft engines. In order to perform efficient and cost-effective overhauls, the maintenance approach is to exchange the modules that caused the removal of...
Article
Full-text available
Long-haul backbone communication networks provide internet services across a region or a country. The access to internet at smaller areas and the functioning of other critical infrastructures rely on the long-haul backbone high speed services and resilience. Hence, such networks are key for the decision-making of internet service managers and provi...