1,547 research outputs found
Assessing and augmenting SCADA cyber security: a survey of techniques
SCADA systems monitor and control critical infrastructures of national importance such as power generation and distribution, water supply, transportation networks, and manufacturing facilities. The pervasiveness, miniaturisations and declining costs of internet connectivity have transformed these systems from strictly isolated to highly interconnected networks. The connectivity provides immense benefits such as reliability, scalability and remote connectivity, but at the same time exposes an otherwise isolated and secure system, to global cyber security threats. This inevitable transformation to highly connected systems thus necessitates effective security safeguards to be in place as any compromise or downtime of SCADA systems can have severe economic, safety and security ramifications. One way to ensure vital asset protection is to adopt a viewpoint similar to an attacker to determine weaknesses and loopholes in defences. Such mind sets help to identify and fix potential breaches before their exploitation. This paper surveys tools and techniques to uncover SCADA system vulnerabilities. A comprehensive review of the selected approaches is provided along with their applicability
Multi-Resolution Functional ANOVA for Large-Scale, Many-Input Computer Experiments
The Gaussian process is a standard tool for building emulators for both
deterministic and stochastic computer experiments. However, application of
Gaussian process models is greatly limited in practice, particularly for
large-scale and many-input computer experiments that have become typical. We
propose a multi-resolution functional ANOVA model as a computationally feasible
emulation alternative. More generally, this model can be used for large-scale
and many-input non-linear regression problems. An overlapping group lasso
approach is used for estimation, ensuring computational feasibility in a
large-scale and many-input setting. New results on consistency and inference
for the (potentially overlapping) group lasso in a high-dimensional setting are
developed and applied to the proposed multi-resolution functional ANOVA model.
Importantly, these results allow us to quantify the uncertainty in our
predictions. Numerical examples demonstrate that the proposed model enjoys
marked computational advantages. Data capabilities, both in terms of sample
size and dimension, meet or exceed best available emulation tools while meeting
or exceeding emulation accuracy
Advanced Applications of Rapid Prototyping Technology in Modern Engineering
Rapid prototyping (RP) technology has been widely known and appreciated due to its flexible and customized manufacturing capabilities. The widely studied RP techniques include stereolithography apparatus (SLA), selective laser sintering (SLS), three-dimensional printing (3DP), fused deposition modeling (FDM), 3D plotting, solid ground curing (SGC), multiphase jet solidification (MJS), laminated object manufacturing (LOM). Different techniques are associated with different materials and/or processing principles and thus are devoted to specific applications. RP technology has no longer been only for prototype building rather has been extended for real industrial manufacturing solutions. Today, the RP technology has contributed to almost all engineering areas that include mechanical, materials, industrial, aerospace, electrical and most recently biomedical engineering. This book aims to present the advanced development of RP technologies in various engineering areas as the solutions to the real world engineering problems
Further Developing a Procedural Digital Twin for Road Tunnels
A Digital Twin is a close to as possible replica of a real world application, in the digital world. The Digital Twin aims to simulate a process, in real time so the user can generate information and value from the process. It is a representation of a physical asset, object or service. Often the Digital Twin takes data from real sensor to mimic the live process in a digital representation. In this thesis, the focus is on Digital Twin representations of road tunnels in Norway. This thesis builds further on previously designed implementation and thesis written at University of Stavanger. The project creates tunnel twins for any given Norwegian tunnel, by using Satens Vegvesen public API for tunnel information.
Extending work made previously that connects static models with generated sensor data to display sensors in a tunnel made in Unity. This thesis furthers develops this project, by aiming to find ways to improve the architecture made in the current implementation while also finding new features to add based on what is seen in other Digital Twins in the academic world. Implementing these new features and changes to see how they are helpful to the continuous work of this Digital Twin project
Adaptive Gaussian process emulators for efficient reliability analysis
This paper presents an approximation method for performing efficient reliability analysis with complex computer models. The computational cost of industrial-scale models can cause problems when performing sampling-based reliability analysis. This is due to the fact that the failure modes of the system typically occupy a small region of the performance space and thus require relatively large sample sizes to accurately estimate their characteristics. The sequential sampling method proposed in this article, combines Gaussian process-based optimisation and subset simulation. Gaussian process emulators construct a statistical approximation to the output of the original code, which is both affordable to use and has its own measure of predictive uncertainty. Subset simulation is used as an integral part of the algorithm to efficiently populate those regions of the surrogate which are likely to lead to the performance function exceeding a predefined critical threshold. The emulator itself is used to inform decisions about efficiently using the original code to augment its predictions. The iterative nature of the method ensures that an arbitrarily accurate approximation of the failure region is developed at a reasonable computational cost. The presented method is applied to an industrial model of a biodiesel filter
An optimization-based control strategy for energy efficiency of discrete manufacturing systems
In order to reduce the global energy consumption and avoid highest power peaks during operation of manufacturing systems, an optimization-based controller for selective switching on/off of peripheral devices in a test bench that emulates the energy consumption of a periodic system is proposed. First, energy consumption models for the test-bench devices are obtained based on data and subspace identification methods. Next, a control strategy is designed based on both optimization and receding horizon approach, considering the energy consumption models, operating constraints, and the real processes performed by peripheral devices. Thus, a control policy based on dynamical models of peripheral devices is proposed to reduce the energy consumption of the manufacturing systems without sacrificing the productivity. Afterward, the proposed strategy is validated in the test bench and comparing to a typical rule-based control scheme commonly used for these manufacturing systems. Based on the obtained results, reductions near 7% could be achieved allowing improvements in energy efficiency via minimization of the energy costs related to nominal power purchased.Peer ReviewedPostprint (author's final draft
Contributions to simulation and emulation of Inter-Satellite Links
Recently, there has been a paradigm shift in space missions. They no longer rely on a single satellite to achieve all the objectives of a mission. Responsibility is shared between devices that can communicate and share resources to achieve these objectives. This paradigm shift has increased the need to assess communication performance within FSS. Despite proposals for simulators and emulators to achieve this goal, none of them integrates the dynamics of satellites with their communications. This thesis presents two proposals and the implementation of one of them to extend the capabilities of the communication channel of the simulator developed by the NanoSat Lab of the UPC. Additionally, following the lines of the i2Cat Space Communications research group, a test bench is also presented to demonstrate the feasibility of a satellite contact emulator. As it will be demonstrated, developing such an emulator has not been possible. Finally, it is concluded that both parts of this thesis may converge. Thus, combining the possibilities offered by the current simulator with those available in the emulator under development.En el transcurso de los Ășltimos años se ha observado un cambio en el paradigma en las misiones espaciales. Ăstas ya no cuentan sĂłlo con un Ășnico satĂ©lite que tenga que alcanzar todos los objetivos de una misiĂłn. Se reparte la responsabilidad entre diferentes dispositivos que son capaces de comunicarse y compartir recursos para alcanzar tales objetivos. De ese cambio de paradigma nace la necesidad de poder evaluar el comportamiento de las comunicaciones dentro de un FSS. A pesar de la existencia de simuladores y propuestas de emuladores para alcanzar tal objetivo, ninguno de ellos integra las dinĂĄmicas de los satĂ©lites con sus comunicaciones. En esta tesis, se presentan dos propuestas y la implementaciĂłn de una de ellas para ampliar las capacidades del canal de comunicaciones del simulador desarrollado por NanoSat Lab de la UPC. AdemĂĄs, siguiendo las lĂneas del grupo de investigaciĂłn de Comunicaciones Espaciales de i2Cat tambiĂ©n se presenta un test-bed para demostrar la viabilidad de un emulador de contactos de satĂ©lites. Pues, como se va a demostrar, el desarrollador de uno como tal no ha sido posible. Por Ășltimo, se concluirĂĄ que ambas partes de esta tesis puedan converger en algĂșn momento combinando asĂ las posibilidades que ofrece el actual simulador con las de un emulador que estĂĄ en desarrollo.En el transcurs dels Ășltims anys sâha observat un canvi en el paradigma de les missions espacials. Aquestes ja no compten nomĂ©s dâun Ășnic satĂšl·lit que hagi dâassolir tots els objectius dâuna missiĂł. Es reparteix la responsabilitat entre diferents dispositius els quals sĂłn capaços de comunicar-se i compartir recursos per tal dâassolir tals objectius. Dâaquest canvi de paradigma neix la necessitat de poder avaluar el comportament de les comunicacions dins dâun FSS. Tot i lâexistĂšncia de simuladors i propostes dâemuladors per assolir tal objectiu, cap dâells integra les dinĂ miques dels satĂšl·lits amb les seves comunicacions. En aquesta tesi, es presenten dues propostes i la implementaciĂł dâuna dâelles per tal dâampliar les capacitats del canal de comunicacions del simulador desenvolupat pel NanoSat Lab de la UPC. A mĂ©s a mĂ©s, seguint les lĂnies del grup de recerca de Comunicacions Espacials d'i2Cat tambĂ© es presenta un test-bed per tal de poder demostrar la viabilitat dâun emulador de contactes de satĂšl·lits. Doncs, com es demostrarĂ , el desenvolupant dâun com a tal no ha estat possible. Finalment, es conclourĂ que ambdues parts d'aquesta tesi puguin convergir en algun moment combinant aixĂ les possibilitat que ofereix l'actual simulador amb les dâun emulador que estĂ en desenvolupamen
MiniCPS: A toolkit for security research on CPS Networks
In recent years, tremendous effort has been spent to modernizing
communication infrastructure in Cyber-Physical Systems (CPS) such as Industrial
Control Systems (ICS) and related Supervisory Control and Data Acquisition
(SCADA) systems. While a great amount of research has been conducted on network
security of office and home networks, recently the security of CPS and related
systems has gained a lot of attention. Unfortunately, real-world CPS are often
not open to security researchers, and as a result very few reference systems
and topologies are available. In this work, we present MiniCPS, a CPS
simulation toolbox intended to alleviate this problem. The goal of MiniCPS is
to create an extensible, reproducible research environment targeted to
communications and physical-layer interactions in CPS. MiniCPS builds on
Mininet to provide lightweight real-time network emulation, and extends Mininet
with tools to simulate typical CPS components such as programmable logic
controllers, which use industrial protocols (Ethernet/IP, Modbus/TCP). In
addition, MiniCPS defines a simple API to enable physical-layer interaction
simulation. In this work, we demonstrate applications of MiniCPS in two example
scenarios, and show how MiniCPS can be used to develop attacks and defenses
that are directly applicable to real systems.Comment: 8 pages, 6 figures, 1 code listin
Low-Cost Inventions and Patents
Inventions have led to the technological advances of mankind. There are inventions of all kinds, some of which have lasted hundreds of years or even longer. Low-cost technologies are expected to be easy to build, have little or no energy consumption, and be easy to maintain and operate. The use of sustainable technologies is essential in order to move towards a greater global coverage of technology, and therefore to improve human quality of life. Low-cost products always respond to a specific need, even if no in-depth analysis of the situation or possible solutions has been carried out. It is a consensus in all industrialized countries that patents have a decisive influence on the organization of the economy, as they are a key element in promoting technological innovation. Patents must aim to promote the technological development of countries, starting from their industrial situations
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