260,872 research outputs found
Recommended from our members
An Autonomic Reliability Improvement System for Cyber-Physical Systems
System reliability is a fundamental requirement of cyber-physical systems. Unreliable systems can lead to disruption of service, financial cost and even loss of human life. Typical cyber-physical systems are designed to process large amounts of data, employ software as a system component, run online continuously and retain an operator-in-the-loop because of human judgment and accountability requirements for safety-critical systems. This paper describes a data-centric runtime monitoring system named ARIS (Autonomic Reliability Improvement System) for improving the reliability of these types of cyber-physical systems. ARIS employs automated online evaluation, working in parallel with the cyber-physical system to continuously conduct automated evaluation at multiple stages in the system workflow and provide real-time feedback for reliability improvement. This approach enables effective evaluation of data from cyber-physical systems. For example, abnormal input and output data can be detected and flagged through data quality analysis. As a result, alerts can be sent to the operator-in-the-loop, who can then take actions and make changes to the system based on these alerts in order to achieve minimal system downtime and higher system reliability. We have implemented ARIS in a large commercial building cyber-physical system in New York City, and our experiment has shown that it is effective and efficient in improving building system reliability
Recommended from our members
Improving System Reliability for Cyber-Physical Systems
Cyber-physical systems (CPS) are systems featuring a tight combination of, and coordination between, the system's computational and physical elements. Cyber-physical systems include systems ranging from critical infrastructure such as a power grid and transportation system to health and biomedical devices. System reliability, i.e., the ability of a system to perform its intended function under a given set of environmental and operational conditions for a given period of time, is a fundamental requirement of cyber-physical systems. An unreliable system often leads to disruption of service, financial cost and even loss of human life. An important and prevalent type of cyber-physical system meets the following criteria: processing large amounts of data; employing software as a system component; running online continuously; having operator-in-the-loop because of human judgment and an accountability requirement for safety critical systems. This thesis aims to improve system reliability for this type of cyber-physical system. To improve system reliability for this type of cyber-physical system, I present a system evaluation approach entitled automated online evaluation (AOE), which is a data-centric runtime monitoring and reliability evaluation approach that works in parallel with the cyber-physical system to conduct automated evaluation along the workflow of the system continuously using computational intelligence and self-tuning techniques and provide operator-in-the-loop feedback on reliability improvement. For example, abnormal input and output data at or between the multiple stages of the system can be detected and flagged through data quality analysis. As a result, alerts can be sent to the operator-in-the-loop. The operator can then take actions and make changes to the system based on the alerts in order to achieve minimal system downtime and increased system reliability. One technique used by the approach is data quality analysis using computational intelligence, which applies computational intelligence in evaluating data quality in an automated and efficient way in order to make sure the running system perform reliably as expected. Another technique used by the approach is self-tuning which automatically self-manages and self-configures the evaluation system to ensure that it adapts itself based on the changes in the system and feedback from the operator. To implement the proposed approach, I further present a system architecture called autonomic reliability improvement system (ARIS). This thesis investigates three hypotheses. First, I claim that the automated online evaluation empowered by data quality analysis using computational intelligence can effectively improve system reliability for cyber-physical systems in the domain of interest as indicated above. In order to prove this hypothesis, a prototype system needs to be developed and deployed in various cyber-physical systems while certain reliability metrics are required to measure the system reliability improvement quantitatively. Second, I claim that the self-tuning can effectively self-manage and self-configure the evaluation system based on the changes in the system and feedback from the operator-in-the-loop to improve system reliability. Third, I claim that the approach is efficient. It should not have a large impact on the overall system performance and introduce only minimal extra overhead to the cyberphysical system. Some performance metrics should be used to measure the efficiency and added overhead quantitatively. Additionally, in order to conduct efficient and cost-effective automated online evaluation for data-intensive CPS, which requires large volumes of data and devotes much of its processing time to I/O and data manipulation, this thesis presents COBRA, a cloud-based reliability assurance framework. COBRA provides automated multi-stage runtime reliability evaluation along the CPS workflow using data relocation services, a cloud data store, data quality analysis and process scheduling with self-tuning to achieve scalability, elasticity and efficiency. Finally, in order to provide a generic way to compare and benchmark system reliability for CPS and to extend the approach described above, this thesis presents FARE, a reliability benchmark framework that employs a CPS reliability model, a set of methods and metrics on evaluation environment selection, failure analysis, and reliability estimation. The main contributions of this thesis include validation of the above hypotheses and empirical studies of ARIS automated online evaluation system, COBRA cloud-based reliability assurance framework for data-intensive CPS, and FARE framework for benchmarking reliability of cyber-physical systems. This work has advanced the state of the art in the CPS reliability research, expanded the body of knowledge in this field, and provided some useful studies for further research
An Ontology-Based Approach To Concern-Specific Dynamic Software Structure Monitoring
Software reliability has not kept pace with computing hardware. Despite the use reliability improvement techniques and methods, faults remain that lead to software errors and failures. Runtime monitoring can improve software reliability by detecting certain errors before failures occur. Monitoring is also useful for online and electronic services, where resource management directly impacts reliability and quality. For example, resource ownership errors can accumulate over time (e. g. , as resource leaks) and result in software aging. Early detection of errors allows more time for corrective action before failures or service outages occur. In addition, the ability to monitor individual software concerns, such as application resource ownership structure, can help support autonomic computing for self-healing, self-adapting and self-optimizing software. This thesis introduces ResOwn - an application resource ownership ontology for interactive session-oriented services. ResOwn provides software monitoring with enriched concepts of application resource ownership borrowed from real-world legal and ownership ontologies. ResOwn is formally defined in OWL-DL (Web Ontology Language Description Logic), verified using an off-the-shelf reasoner, and tested using the call processing software for a small private branch exchange (PBX). The ResOwn Prime Directive states that every object in an operational software system is a resource, an owner, or both simultaneously. Resources produce benefits. Beneficiary owners may receive resource benefits. Nonbeneficiary owners may only manage resources. This approach distinguishes resource ownership use from management and supports the ability to detect when a resource's role-based runtime capacity has been exceeded. This thesis also presents a greybox approach to concern-specific, dynamic software structure monitoring including a monitor architecture, greybox interpreter, and algorithms for deriving monitoring model from a monitored target's formal specifications. The target's requirements and design are assumed to be specified in SDL, a formalism based on communicating extended finite state machines. Greybox abstraction, applicable to both behavior and structure, provides direction on what parts, and how much of the target to instrument, and what types of resource errors to detect. The approach was manually evaluated using a number of resource allocation and ownership scenarios. These scenarios were obtained by collecting actual call traces from an instrumented PBX. The results of an analytical evaluation of ResOwn and the monitoring approach are presented in a discussion of key advantages and known limitations. Conclusions and recommended future work are discussed at the end of the thesis
Remote operation and monitoring of a micro aero gas turbine
Internet applications have been extended to various aspects of everyday life and offer services of high reliability and security at relatively low cost. This project presents the design of a reliable, safe and secure software system for real-time remote operation and monitoring of an aero gas turbine with utilisation of existing internet technology, whilst the gas turbine is installed in a remote test facility
This project introduces a capability that allows remote and flexible operation of an aero gas turbine throughout the whole operational envelope, as required by the user at low cost, by exploiting the available Internet technology. Remote operation of the gas turbine can be combined with other remote Internet applications to provide very powerful gas-turbine performance-simulation experimental platforms and real-time performance monitoring tools, whilst keeping the implementation cost at low levels.
The gas turbine used in this experiment is an AMT Netherlands Olympus micro gas turbine and a spiral model approach was applied for the software. The whole process was driven by risk mitigation.
The outcome is a fully functional software application that enables remote operation of the micro gas turbine whilst constantly monitors the performance of the engine according to basic gas turbine control theory. The application is very flexible, as it runs with no local installation requirements and includes provisions for expansion and collaboration with other online performance simulation and diagnostic tools.
This paper will be presented at the ISABE 2017 Conference, 5-8 September 2017, Manchester, UK
Evaluasi Kualitas Online Monitoring Sistem Perbendaharaan Dan Anggaran Negara Berdasarkan Aspek Integrity, Correctness, Dan Reliability - Quality Evaluation Of Online Monitoring System Of Treasury And State Budget Based On Integrity, Correctness And Reliability Aspects
Aplikasi Online Monitoring Sistem Perbendaharaan dan
Anggaran Negara (OM SPAN) merupakan aplikasi
pendukung Sistem Perbendaharaan dan Anggaran Negara
(SPAN) yang menjalankan fungsi monitoring atas
transaksi di dalam sebuah sistem yang mengintegrasikan
pengelolaan perbendaharaan dan anggaran negara. Data
dan informasi yang dikelola merupakan data yang sangat
penting yaitu terkait pengelolaan keuangan dan anggaran
negara. Mengingat krusialnya data yang diolah dan yang
ditampilkan pada aplikasi ini, dibutuhkan sebuah evaluasi
kualitas guna meninjau bagaimana kualitas yang
disajikan serta dikarenakan belum pernah dilakukan
evaluasi kualitas atas aplikasi ini sebelumnya. Di dalam
McCall Quality Model terdapat sebelas faktor evaluasi
kualitas perangkat lunak antara lain : correctness,
reliability, efficiency, integrity, usability, maintainability,
testability, flexibility, portability, reusability, dan
interoperability. Penelitian Tugas Akhir ini bertujuan
untuk memaparkan evaluasi kualitas aplikasi OM SPAN ditinjau dari aspek Integrity, Correctness dan Reliability.
Tiap-tiap aspek memiliki beberapa kriteria kualitas yang
diukur berdasarkan metrik pada ISO/IEC 9126:2002.
Evaluasi kualitas ini didasarkan pada wawancara,
kuesioner , observasi langsung, pengujian berdasarkan
test case scenario dan pengumpulan data/dokumentasi
arsip. Hasil pengujian ini kemudian dihitung dengan
formula Bowen untuk tiap aspek kualitas. Untuk aspek
integrity diperoleh nilai 100% sebagai indikasi suksesnya
pelaksanaan access audit dan monitoring akses user.
Untuk aspek correctness diperoleh skor 95,87% atas
kesesuaian dan ketepatan (correctness) implementasi
kebutuhan fungsional. Sedangkan untuk aspek reliability
mendapatkan nilai 95,25% untuk kehandalan (reliability)
aplikasi OM SPAN di dalam menyajikan data dan
informasi yang tepat dan akurat. Selanjutnya
penyampaian rekomendasi atas hasil evaluasi kualitas
kepada pihak pengembang guna kebutuhan perbaikan dan
peningkatan kualitas aplikasi Online Monitoring Sistem
Perbendaharaan dan Anggaran Negara pada masa
mendatang.
========================================================================================================================
Online Monitoring System of Treasury And State Budget (OM
SPAN) is supporting application of Treasury and the State
Budget System (SPAN) that performs transaction monitoring
function within a system that integrates the management of the
treasury and the state budget. The data and information are
managed in this system are highly important that is related to
financial management and the state budget. Given the crucial
data is processed and displayed in this application, a quality
evaluation is required to observe how the quality being served
as well as the evaluation has not been done due to the quality
of the application before. In McCall Quality Model there are
eleven software quality evaluation factors, among others:
correctness, reliability, efficiency, integrity, usability,
maintainability, testability, flexibility, portability, reusability
and interoperability. This paper aims to describe the quality
evaluation of OM SPAN application in terms of Integrity,
Correctness and Reliability aspects. Each aspects has several
quality criteria that are measured by the metric on ISO/IEC
9126:2002. This quality evaluation is based on interviews, questionnaires,
direct observation, testing based on test case scenarios and
data collection / documentation archives. The test results are
calculated by the Bowen’s formula for each quality aspects.
For the integrity aspect has value 100% as an indication of the
successful implementation of access audit and monitoring user
access. For the correctness aspect obtained 95,87% of the
suitability and correctness the implementation of functional
requirements. As for the aspect of reliability scores 95,25% for
reliability of OM SPAN application is presenting data and
information which is precise and accurate. The next delivery
of recommendations over the quality of the evaluation results
to the developer in order to repair and quality improvement
Online Monitoring System of Treasury and State Budget
application in the future
Real-Time Monitoring and Control of Ultra-Fast Laser Engraving Process Utilizing Spectrometer
The objective of this study was to develop a novel real-time monitoring and control method for ultra-fast laser scribing processes utilizing spectrometer. Adjustment of laser process parameters such as laser power with high precision in real-time is critical in the laser engraving process due to the premium quality and speed requirements of the process. An online monitoring system was established using the Ocean Optics spectrometer, IPG ytterbium pulsed laser, and PXIe-8880 industrial computer. An algorithm for real-time control of the laser scribing process was developed based on the monitoring outcomes using LabVIEWⓇ software. Experimental methods were performed to evaluate the reliability of the developed monitoring system and control algorithm. The sensitivity of the spectrometer was assessed by changing laser power, pulse length, and focal point position. A workpiece consisting of two different metals, including stainless steel SS304L and steel S355, was used to evaluate the performance of the developed algorithm when scribing moved from one material to another. Instant accurate setting of the laser power based on the variations in intensities of metals from 750 AU to 1400 AU validated the reliability of the algorithm.</p
Recommended from our members
An Approach to Using Non Safety-Assured Programmable Components in Modest Integrity Systems
Programmable components (like personal computers or smart devices) can offer considerable benefits in terms of usability and functionality in a safety-related system. However there is a problem in justifying the use of programmable components if the components have not been safety justified to an appropriate integrity (e.g. to SIL 1 of IEC 61508). This paper outlines an approach (called LowSIL) developed in the UK CINIF nuclear industry research programme to justify the use of non safety-assured programmable components in modest integrity systems. This is a seven step approach that can be applied to new systems from an early design stage, or retrospectively to existing systems. The stages comprise: system characterisation, component suitability assessment, failure analysis, failure mitigation, identification of additional defences, identification of safety evidence requirements, and collation and evaluation of evidence. In the case of personal computers, there is supporting guidance on usage constraints, claim limits on reliability, and advice on “locking down” the component to maximise reliability. The approach is demonstrated for an example system. The approach has been applied successfully to a range of safety-related systems used in the nuclear industry
Wind turbine condition monitoring : technical and commercial challenges.
Deployment of larger scale wind turbine systems, particularly offshore, requires more organized operation and maintenance strategies to ensure systems are safe, profitable and cost-effective. Among existing maintenance strategies, reliability centred maintenance is regarded as best for offshore wind turbines, delivering corrective and proactive (i.e. preventive and predictive) maintenance techniques enabling wind turbines to achieve high availability and low cost of energy. Reliability centred maintenance analysis may demonstrate that an accurate and reliable condition monitoring system is one method to increase availability and decrease the cost of energy from wind. In recent years, efforts have been made to develop efficient and cost-effective condition monitoring techniques for wind turbines. A number of commercial wind turbine monitoring systems are available in the market, most based on existing techniques from other rotating machine industries. Other wind turbine condition monitoring reviews have been published but have not addressed the technical and commercial challenges, in particular, reliability and value for money. The purpose of this paper is to fill this gap and present the wind industry with a detailed analysis of the current practical challenges with existing wind turbine condition monitoring technology
Advanced Techniques for Assets Maintenance Management
16th IFAC Symposium on Information Control Problems in Manufacturing INCOM 2018
Bergamo, Italy, 11–13 June 2018. Edited by Marco Macchi, László Monostori, Roberto PintoThe aim of this paper is to remark the importance of new and advanced techniques supporting decision making in different business processes for maintenance and assets management, as well as the basic need of adopting a certain management framework with a clear processes map and the corresponding IT supporting systems. Framework processes and systems will be the key fundamental enablers for success and for continuous improvement. The suggested framework will help to define and improve business policies and work procedures for the assets operation and maintenance along their life cycle. The following sections present some achievements on this focus, proposing finally possible future lines for a research agenda within this field of assets management
Internet of Things-aided Smart Grid: Technologies, Architectures, Applications, Prototypes, and Future Research Directions
Traditional power grids are being transformed into Smart Grids (SGs) to
address the issues in existing power system due to uni-directional information
flow, energy wastage, growing energy demand, reliability and security. SGs
offer bi-directional energy flow between service providers and consumers,
involving power generation, transmission, distribution and utilization systems.
SGs employ various devices for the monitoring, analysis and control of the
grid, deployed at power plants, distribution centers and in consumers' premises
in a very large number. Hence, an SG requires connectivity, automation and the
tracking of such devices. This is achieved with the help of Internet of Things
(IoT). IoT helps SG systems to support various network functions throughout the
generation, transmission, distribution and consumption of energy by
incorporating IoT devices (such as sensors, actuators and smart meters), as
well as by providing the connectivity, automation and tracking for such
devices. In this paper, we provide a comprehensive survey on IoT-aided SG
systems, which includes the existing architectures, applications and prototypes
of IoT-aided SG systems. This survey also highlights the open issues,
challenges and future research directions for IoT-aided SG systems
- …