Dissertationen: „Specification of cyberphysical systems“

1

Junek, Martin. „Metody specifikace kyberfyzikálních systémů“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-442854.

Der volle Inhalt der Quelle

Annotation:

The aim of this diploma thesis is to analyse the advantages and disadvantages of different types of description of cyberphysical systems. It also concerns a description of the selected method that meets most of the current requirements for CPS design. In the practical part, attention is paid to the elaboration of an example for the specification of a selected cyberphysical system.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

2

Chabukswar, Rohan. „Secure Detection in Cyberphysical Control Systems“. Research Showcase @ CMU, 2014. http://repository.cmu.edu/dissertations/326.

Der volle Inhalt der Quelle

Annotation:

A SCADA system employing the distributed networks of sensors and actuators that interact with the physical environment is vulnerable to attacks that target the interface between the cyber and physical subsystems. An attack that hijacks the sensors in an attempt to provide false readings to the controller (for example, the Stuxnet worm that targeted Iran’s nuclear centrifuges) can be used to feign normal system operation for the control system, while the attacker can hijack the actuators to send the system beyond its safety range. This thesis extends the results of a previously proposed method. The original method proposed addition of a randomized “watermarking” signal and checking for the presence of this signal and its effects in the received sensor measurements. Since the control inputs traverse the cyberphysical boundary and make their effects apparent in the sensor measurements, they are employed to carry this watermarking signal through to the system and back to the SCADA controller. The sensor measurements are compared to the expected measurements (calculated using a suitably delayed model of the system within the controller). This methodology is based on using the statistics of the linear system and its controller. The inclusion of a randomized signal on the control inputs induces an increase in the performance cost of the physical system. This thesis proposes a method of optimization of the watermarking signal based on the trade-off between this performance cost and the attack detection rate, by leveraging the distribution the watermarking signal over multiple inputs and multiple outputs. It is further proved that regardless of the number of inputs and outputs in the system, only one watermarking signal needs to be generated. This optimization, and its necessity in improving the effectiveness of the detector without detriment to the performance cost, are demonstrated on a simulated chemical plant. The thesis also proposes another methodology that does not rely on these statistics, but is instead based on calculating the correlation between the received sensor measurements and the expected measurements accrued from the model inside the controller. Generalizing the form of attack even further to attacks that target the integrity of the data sent to the actuators and received from the sensors, this thesis demonstrates the effect of such integrity attack on electricity market operations, where the attacker successfully uses a vulnerability in the Global Position System to break synchronicity among dispersed phasor measurements to gain a competitive advantage over other bidders in the electricity market. In an effort to make state estimation robust against integrity attacks, the sensors and states are modeled as binary variables. Sensor networks use binary measurements and state estimations for several reasons, including communication and processing overheads. Such a state estimator is vulnerable to attackers that can hijack a subset of the sensors in an effort to change the state estimate. This thesis proposes a method for designing the estimators using the concept of invariant sets. This methodology relies on identifying the sets of measurement vectors for which no amount of manipulation by the attacker can change estimate, and maximizing the probability that the sensor measurement vector lies in this set. Although the problem of finding the best possible invariant sets for a general set of sensors has double-exponential complexity, by using some simplifications on the types of sensors, this can be reduced significantly. For the problem that employs all sensors of the same type, this method reduces to a linear search. For sensors that can be classified into two types, this complexity reduces to a search over a two-dimensional space, which is still tractable. Further increase in the confidence of the estimate can be achieved by considering the correlation between the sensor measurements.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

3

Magnússon, Sindri. „Bandwidth Limited Distributed Optimization with Applications to Networked Cyberphysical Systems“. Doctoral thesis, KTH, Nätverk och systemteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-205682.

Der volle Inhalt der Quelle

Annotation:

The emerging technology of Cyberphysical systems consists of networked computing, sensing, and actuator devices used to monitor, connect, and control physical phenomena. In order to economically and sustainably operate Cyberphysical systems, their devices need to cooperate over a communication network to solve optimization problems. For example, in smart power grids, smart meters cooperatively optimize the grid performance, and in wireless sensor networks a number of sensors cooperate to find optimal estimators of real-world parameters. A challenging aspect in the design of distributed solution algorithms to these optimization problems is that while the technology advances and the networks grow larger, the communication bandwidth available to coordinate the solution remains limited. Motivated by this challenge, this thesis investigates the convergence of distributed solution methods for resource allocation optimization problems, where gradient information is communicated at every iteration, using limited communication. This problem is approached from three different perspectives, each presented in a separate paper. The investigation of the three papers demonstrate promises and limits of solving distributed resource allocation problems using limited communication bandwidth. Future work will consider how even more general problems can be solved using limited communication bandwidth and also study different communication constraints.

QC 20170424

APA, Harvard, Vancouver, ISO und andere Zitierweisen

4

Ehikioya, Sylvanus Agbonifoh. „Specification of transaction systems protocols“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/nq23597.pdf.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

5

Hunter, Timothy Jason. „Large-Scale, Low-Latency State Estimation Of Cyberphysical Systems With An Application To Traffic Estimation“. Thesis, University of California, Berkeley, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3686329.

Der volle Inhalt der Quelle

Annotation:

Large physical systems are increasingly prevalent, and designing estimation strategies for them has become both a practical necessity and a complicated problem. Their sensing infrastructure is usually ad-hoc, and the estimate of interest is often a complex function of the data. At the same time, computing power is rapidly becoming a commodity. We show with the study of two estimation tasks in urban transportation how the proper design of algorithms can lead to significant gains in scalability compared to existing solutions.

A common problem in trip planning is to make a given deadline such as arriving at the airport within an hour. Existing routing services optimize for the expected time of arrival, but do not provide the most reliable route, which accounts for the variability in travel times. Providing statistical information is even harder for trips in cities which undergo a lot of variability. This thesis aims at building scalable algorithms for inferring statistical distributions of travel time over very large road networks, using GPS points from vehicles in real-time. We consider two complementary algorithms that differ in the characteristics of the GPS data input, and in the complexity of the model: a simpler streaming Expectation-Maximization algorithm that leverages very large volumes of extremely noisy data, and a novel Markov Model-Gaussian Markov Random Field that extracts global statistical correlations from high-frequency, privacy-preserving trajectories.

These two algorithms have been implemented and deployed in a pipeline that takes streams of GPS data as input, and produces distributions of travel times accessible as output. This pipeline is shown to scale on a large cluster of machines and can process tens of millions of GPS observations from an area that comprises hundreds of thousands of road segments. This is to our knowledge the first research framework that considers in an integrated fashion the problem of statistical estimation of traffic at a very large scale from streams of GPS data.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

6

Miranda, Paul Nicholas. „HD4AR: High-Precision Mobile Augmented Reality Using Image-Based Localization“. Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/77013.

Der volle Inhalt der Quelle

Annotation:

Construction projects require large amounts of cyber-information, such as 3D models, in order to achieve success. Unfortunately, this information is typically difficult for construction field personnel to access and use on-site, due to the highly mobile nature of the job and hazardous work environments. Field personnel rely on carrying around large stacks of construction drawings, diagrams, and specifications, or traveling to a trailer to look up information electronically, reducing potential project efficiency. This thesis details my work on Hybrid 4-Dimensional Augmented Reality, known as HD4AR, a mobile augmented reality system for construction projects that provides high-precision visualization of semantically-rich 3D cyber-information over real-world imagery. The thesis examines the challenges related to augmenting reality on a construction site, describes how HD4AR overcomes these challenges, and empirically evaluates the capabilities of HD4AR.
Master of Science

APA, Harvard, Vancouver, ISO und andere Zitierweisen

7

Reynolds, Graham J. „Configurable graphics systems : modelling and specification“. Thesis, University of East Anglia, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293731.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

8

Donnelly, Ronald Patrick. „Modelling and specification of payload systems“. Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261668.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

9

Davies, Jim. „Specification and proof in real-time systems“. Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279830.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

10

Ebner, Michael. „UML-based Test Specification for Communication Systems“. Doctoral thesis, [S.l.] : [s.n.], 2004. http://hdl.handle.net/11858/00-1735-0000-0006-B3B4-9.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

11

Kutar, Maria Shereen. „Specification of temporal properties of interactive systems“. Thesis, University of Hertfordshire, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365935.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

12

Memmel, Thomas. „User interface specification for interactive software systems /“. Boizenburg : Hülsbusch, 2009. http://d-nb.info/997400234/04.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

13

Ubhayakar, Sonali S. „Evalutation of program specification and verification systems“. Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Jun%5FUbhayakar.pdf.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

14

Fridella, Stephen Anthony. „Incremental specification and verification of object systems /“. The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488199501405076.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

15

Ubhayakar, Sonali S. „Evaluation of program specification and verification systems“. Thesis, Monterey, California. Naval Postgraduate School, 2003. http://hdl.handle.net/10945/893.

Der volle Inhalt der Quelle

Annotation:

Computer systems that earn a high degree of trust must be backed by rigorous verification methods. A verification system is an interactive environment for writing formal specifications and checking formal proofs. Verification systems allow large complicated proofs to be managed and checked interactively. We desire evaluation criteria that provide a means of finding which verification system is suitable for a specific research environment and what needs of a particular project the tool satisfies. Therefore, the purpose of this thesis is to develop a methodology and set of evaluation criteria to evaluate verification systems for their suitability to improve the assurance that systems meet security objectives. A specific verification system is evaluated with respect to the defined methodology. The main goals are to evaluate whether the verification system has the capability to express the properties of software systems and to evaluate whether the verification system can provide inter-level mapping, a feature required for understanding how a system meets security objectives.
Naval Postgraduate School author (civilian).

APA, Harvard, Vancouver, ISO und andere Zitierweisen

16

Auddino, Annamaria. „A language for multilevel specification of information systems /“. [S.l.] : [s.n.], 1995. http://library.epfl.ch/theses/?nr=1384.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

17

Tyler, Benjamin James. „Specification and runtime monitoring of object-oriented systems“. Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1143228898.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

18

Schäfer, Andreas. „Specification and verification of mobile real-time systems /“. Oldenburg : Univ., Fak. II, Dep. für Informatik, 2006. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=015580252&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

19

Hooman, Jozef. „Specification and compositional verification of real time systems /“. Berlin [u.a.] : Springer, 1991. http://www.loc.gov/catdir/enhancements/fy0815/91041783-d.html.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

20

Schäfer, Andreas. „Specification and verification of mobile real-time systems /“. Oldenburg : Carl-von-Ossietzky-Univ., Dept. für Informatik, 2007. http://www.gbv.de/dms/ilmenau/toc/525193227.PDF.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

21

Artikis, Alexander. „Executable specification of open norm-governed computational systems“. Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.411598.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

22

Hirani, Hitendra J. „Knowledge based requirements specification for reconfigurable assembly systems“. Thesis, University of Nottingham, 2005. http://eprints.nottingham.ac.uk/14575/.

Der volle Inhalt der Quelle

Annotation:

Automated assembly technology may be the key to sustaining manufacturing industry in more developed countries. Currently this comprises dedicated systems that can assemble single products at high volumes and flexible systems to assemble a wide variety of products in low volumes. However, competitive forces demand a compromise between the two and Reconfigurable Assembly Systems are an avenue for achieving high volume and high variety production. Although this technology is coming to the fore, there is a distinct lack of tools and methods that make the prospect attractive to key decision makers in organisations. Reconfigurable solutions, which may be profitable in the long term, are rejected in favour of short term solutions, which prove to be more expensive over time. The benefits of requirements engineering have been exploited in software engineering and this work demonstrates how these can be adapted to an assembly environment to form a new basis for communication between the system vendors, who supply assembly system solutions, and system users, who use them. Knowledge Engineering has become a key aspect in industry due to the challenges of retaining personnel and their knowledge within organisations. This is because employees take their knowledge of the organisation with them when they leave. The retention of this knowledge would help to maintain the continuity within organisations. This thesis reports on research that aims to provide a means to integrate these three aspects to form a basis for sustaining competitive manufacture in more developed countries. Moreover, Knowledge Based Requirements Specification for Reconfigurable Assembly Systems will provide a vital medium for promoting Reconfigurable Assembly Systems and encourage their implementation by providing a knowledge-based platform for the specification of Reconfigurable Assembly Systems.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

23

Androutsopoulos, Kalliopi. „Specification and verification of reactive systems with RSDS“. Thesis, King's College London (University of London), 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414509.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

24

Habashi, Esmaeil. „Specification and design of large computer-based systems“. Thesis, University of Sussex, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295980.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

25

Stephens, Owen. „Compositional specification and reachability checking of net systems“. Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/385201/.

Der volle Inhalt der Quelle

Annotation:

Concurrent systems are frequently scrutinised using automated model checking, routinely using Petri nets as a model. While for small system models, it is often sufficient to give the system specification in a monolithic manner, for larger systems this approach is infeasible. Instead, a compositional, or component-wise specification can be used. However, while existing model checking techniques sometimes allow the specification of nets in terms of components, the techniques used for checking properties of the system all consider the composed, global net. In this thesis, we investigate and advocate compositional system specification and an alternative approach to model checking that uses the structural compositional information to its advantage, vastly improving efficiency in many examples. In particular, we examine the categorical structure of component nets and their semantics, illustrating the functoriality of a map between the categories as compositionality. We introduce contextual Petri Nets with Boundaries (PNBs), adding read arcs, which naturally model behaviour that non-destructively reads the token state of a place. Furthermore, we introduce a type-checked specification language that allows us to compositionally construct systems to be modelled using PNBs, whilst ensuring that only correct compositions are expressible. We then discuss and implement compositional statespace generation, which can be used to check reachability. Via optimisations using weak language equivalence and memoisation, we obtain substantial speed ups and demonstrate that our checker outperforms the current state-of-the-art for several examples. A final contribution is the compositional specification of existing benchmark examples, in more natural, component-wise style.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

26

Martin, Frank A. „Tutoring systems based on user-interface dialogue specification“. Thesis, University of Greenwich, 1990. http://gala.gre.ac.uk/8685/.

Der volle Inhalt der Quelle

Annotation:

This thesis shows how the appropriate specification of a user interface to an application software package can be used as the basis for constructing a tutorial for teaching the use of that interface. An economy can hence be made by sharing the specification between the application development and tutorial development stages. The major part of the user-interface specification which is utilised, the task classification structure, must be transformed from an operational to a pedagogic ordering. Heuristics are proposed to achieve this, although human expertise is required to apply them. The report approach is best suited to domains with hierarchically-ordered command sets. A portable rule-based shell has been developed in Common Lisp which supports the delivery of tutorials for a range of software application package interfaces. The use of both the shell and tutorials for two such interfaces is reported. A computer-based authoring environment provides support for tutorial development. The shell allows the learner of a software interface to interact directly with the application software being learnt while remaining under tutorial control. The learner can always interrupt in order to request a tutorial on any topic, although advice may be offered against this in the light of the tutor's current knowledge of the learner. This advice can always be over-ridden. The key-stroke sequences of the tutorial designer and the learner interacting with the package are parsed against an application model based on the task classification structure. Diagnosis is effected by a differential modelling technique applied to the structures generated by the parsing processes. The approach reported here is suitable for an unsupported software interface learner and is named LIY (`Learn It Yourself'). It provides a promising method for augmenting a software engineering tool-kit with a new technique for producing tutorials for application software.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

27

Cansado, Antonio. „Formal specification and verification of distributed component systems“. Nice, 2008. http://www.theses.fr/2008NICE4052.

Der volle Inhalt der Quelle

Annotation:

Les composants sont des blocs logiciels qui communiquent par des interfaces bien définies. Ces interfaces définissent un contrat avec l'environnement. Ce contrat doit garantir la compatibilité comportementale des interfaces. Cette compatibilité est en particulier importante quand des composants sont distribués et communiquent par des méthodes asynchrones. Cette thèse se base sur les spécifications comportementales des composants distribués. Nous développons un cadre formel qui nous permet de construire des modèles comportementaux pour ces composants. Après une phase d'abstraction, ces modèles peuvent être utilisés en entrée pour des outils de vérification modernes. L'objectif principal est de spécifier, vérifier et au final de produire des composants distribués avec un comportement garanti. Pour ce faire, nous développons une langage de spécifications proche de Java. Ce langage est établi sur notre modèle comportemental, et fournit une abstraction puissante de haut niveau du système. Les avantages sont les suivants: (i) nous pouvons nous connecter avec des outils de vérification: ainsi nous sommes capables de vérifier plusieurs sortes de propriétés ; et (ii), les spécifications sont assez complètes pour produire des squelettes de code de contrôle des composants. Finalement, nous validons notre approche avec un cas d'étude à l'aide d'un exemple commun de système à composants (``Common Component Model Example (CoCoME)''). Les particularités du langage proposé sont : traiter des composants hiérarchiques qui communiquent par des appels de méthodes asynchrones; donner le comportement d'un composant comme l'ensemble de services; utiliser une sémantique proche d'un langage de programmation; et traiter des abstractions de code utilisateur
Components are self-contained building blocks. They communicate through well-defined interfaces, that set some kind of contract. This contract must guarantee the behavioural compatibility of bound interfaces. This is particularly true when components are distributed and communicate through asynchronous method calls. This thesis addresses the behavioural specification of distributed components. We develop a formal framework that allows us to build behavioural models. After abstraction, these models are a suitable input for state-of-the-art verification tools. The main objective is to specify, to verify, and to generate safe distributed components. To this aim, we develop a specification language close to Java. This language is built on top of our behavioural model, and provides a powerful high-level abstraction of the system. The benefits are twofold: (i) we can interface with verification tools, so we are able to verify various kinds of properties; and (ii), the specification is complete enough to generate code-skeletons defining the control part of the components. Finally, we validate our approach with a Point-Of-Sale case-study under the Common Component Model Example (CoCoME). The specificities of the specification language proposed in this thesis are: to deal with hierarchical components that communicate by asynchronous method calls; to give the component behaviour as a set of services; and to provide semantics close to a programming language by dealing with abstractions of user-code

APA, Harvard, Vancouver, ISO und andere Zitierweisen

28

Barros, Tomás. „Formal specification and verification of distributed component systems“. Nice, 2005. http://www.theses.fr/2005NICE4048.

Der volle Inhalt der Quelle

Annotation:

Les phospholipases A2 sécrétées (sPLA2) sont de puissants inhibiteurs de l’entrée du virus de l’immunodéficience humaine (HIV) (Fenard et al. , 1999). Afin de mieux comprendre leur mécanisme d’action, nous avons cloné un HIV résistant à la sPLA2 de venin d’abeille (bvPLA2), HIVRBV-3. Mon projet de thèse a consisté en l’élucidation des mécanismes moléculaires qui confèrent sa résistance à HIVRBV-3. Il est bien documenté que le HIV pénétrant dans la cellule par fusion de la membrane virale avec la membrane plasmique. Par ailleurs, il est généralement admis que les HIV pénétrant dans la cellule par la voie endosomale sont dégradés dans les lysosomes et ne sont donc pas infectieux. Nous avons montré, avec trois techniques d’analyse différentes, que la voie d’entrée de HIVRBV-3 est dépendante des endosomes et de leurs moteurs cytosqueletiques. En effet, la réplication de HIVRBV-3 est sensible à plusieurs types d’inhibiteurs de l’acidification des endosomes et de la polymérisation des micro-filaments d’actine et ce, dans différents types cellulaires. Nous montrons que ce mécanisme d’entrée original ainsi que la résistance à bvPLA2 sont supportés par la glycoprotéine d’enveloppe (gp160) de HIVRBV-3. Nos recherches en cours consistent à démontrer l’implication de modification singulière de certaines boucles variables de la gp120 de HIVRBV-3 dans ce mécanisme d’entrée inédit. Les données de la bibliographie indiquent que ces modifications de la gp120 sont retrouvées dans les souches virales isolées chez les patients non progresseurs à long terme. Notre hypothèse actuelle est donc que les sPLA2 humaines pourraient jouer un rôle dans le contrôle de la réplication virale chez ces individus
Secreted phospholipases A2 (sPLA2) are potent inhibitors of Human Immunodeficiency Virus (HIV) replication. In order to gain insights of their antiviral effects we have cloned a bee-venom sPLA2 (bvPLA2) resistant HIV strain, HIVRBV-3. Our goal is to elucidate the molecular mechanisms that confer bvPLA2 resistance to HIVRBV-3. HIV enters cell via fusion o viral and plasma membrane. Furthermore, it is generally admitted that HIV endosomal entry is a dead end route of infection. We show that HIVRBV-3 entry is highly dependent on the molecular mechanisms of endocytosis, particularly those of vesicular trafficking. We were able to show, using three different ways of investigation, that HIVRBV-3 replication in different cell lines is inhibited by lysosomotropic agents, and by drug that affect the cytoskeleton (actin microfilaments and microtubules) polymerization. We further demonstrate that HIVRBV-3 envelope glycoprotein directs HIVRBV-3 in this particularly entry route and that is sufficient to confer bvPLA2 resistance to a HIV bfPLA2 sensitive strain. We are currently investigating the role played by uncommon mutations in the variable loops of HIVRBV-3 envelope glycoprotein, in directing the HIVRBV-3 entry pathway. These uncommon mutations are also specific of long-term non-progressor HIV strains? This lead us to assess the role played by endogenous human sPLA2 in the physiopathology of the HIV infection. Altogether our results suggest a new resistance mechanism at the cellular level. Indeed, HIV may overcome the inhibitory effect of an intracytoplasmic block by using an alternative entry pathway

APA, Harvard, Vancouver, ISO und andere Zitierweisen

29

Delahaye, Benoît. „Modular specification and compositional analysis of stochastic systems“. Rennes 1, 2010. http://www.theses.fr/2010REN1S091.

Der volle Inhalt der Quelle

Annotation:

Cette thèse présente des contributions originales pour la conception et la vérification de systèmes non déterministes et stochastiques. Nos résultats sont divisés selon trois lignes directrices. Premièrement, nous généralisons la théorie des interfaces au cas stochastique, en s'appuyant sur le formalisme classique des chaînes de Markov à intervalles pour construire la première théorie de spécification compositionnelle pour systèmes stochastiques : les chaînes de Markov à contraintes. Deuxièmement, nous étendons la notion de contrats hypothèse-garantie et développons une théorie compositionnelle à base de contrats pour systèmes stochastiques, pour laquelle nous proposons des notions quantitatives de raffinement et de satisfaction. Finalement, nous proposons une méthodologie pour la vérification de systèmes complexes, basée sur une abstraction stochastique. Cette méthodologie, combinée avec le model-checking statistique, est appliquée avec succès à un cas d'étude industriel
This thesis presents new contributions in the design and verification of systems mixing both non deterministic and stochastic aspects. Our results can be divided into three main contributions. First, we generalize interface theories to the stochastic setting. We build upon the known formalism of Interval Markov Chains to develop Constraint Markov Chains, the first fully compositional specification theory for stochastic systems. Second, we extend the notion of assume-guarantee contracts and develop a contract-based theory for stochastic systems, proposing quantitative notions for satisfaction and refinement. Finally, we propose a methodology for the verification of complex systems. This methodology is based on a stochastic abstraction of the environment where two components are working, allowing to verify the components individually. Combined with statistical model checking, this methodology is successfully applied to the verification of an industrial case study

APA, Harvard, Vancouver, ISO und andere Zitierweisen

30

McClenaghan, Ashley. „Distributed systems : architecture-driven specification using extended LOTOS“. Thesis, University of Stirling, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357056.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

31

Azumi, Takuya, Masanari Yamamoto, Yasuo Kominami, Nobuhisa Takagi, Hiroshi Oyama und Hiroaki Takada. „A New Specification of Software Components for Embedded Systems“. IEEE, 2007. http://hdl.handle.net/2237/9438.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

32

Tanir, Oryal. „Specification driven architectural modelling environment for telecommunication systems synthesis“. Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28537.

Der volle Inhalt der Quelle

Annotation:

Design automation has steadily contributed to improvements witnessed in the system design process. Initial applications were to address low level design concerns such as transistor layout and simulation; however the focus of tools has slowly been progressing up the design abstraction scale. The current state-of-the-art provides modelling capabilities at different levels of abstraction, but solutions for synthesis issues at the register-transfer and lower levels are the norm. The proliferation of design description languages at different abstraction levels has prompted the need for standardization (VHDL and Open-Verilog) to promote design migration and re-use.
While design automation has helped in reducing design time-lines and design churn, a major source of design difficulties is just recently being addressed and promise to be the next wave in design automation applicability. The problems arise within the architectural (or system) level of abstraction very early in the design cycle. The recent research in this field attempts to bridge the design process gap between specification and design, and provides a platform for experimenting with hardware and software trade-offs.
This dissertation studies the requirements for an environment for architectural design. In particular, an environment specific to the telecommunications domain is proposed in order to limit the potentially large design exploration space. An intermediate design language is also introduced to accommodate both high level modelling and synthesis driven by the user and environment. Finally a Design Analysis and Synthesis Environment (DASE) is described to facilitate the architectural level activities. The environment, a proof of concept, provides generic modal library, simulation, synthesis and Petri-net analysis support. Realistic design examples are explored, to illustrate architectural design activities with the environment.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

33

Gurov, Dilian Borissov. „Specification and verification of communicating systems with value passing“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ34264.pdf.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

34

Blair, Lynne. „The formal specification and verification of distributed multimedia systems“. Thesis, Lancaster University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282373.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

35

Butterworth, Richard J. „A formal framework for the specification of interactive systems“. Thesis, Loughborough University, 1997. https://dspace.lboro.ac.uk/2134/14163.

Der volle Inhalt der Quelle

Annotation:

We are primarily concerned with interactive systems whose behaviour is highly reliant on end user activity. A framework for describing and synthesising such systems is developed. This consists of a functional description of the capabilities of a system together with a means of expressing its desired 'usability'. Previous work in this area has concentrated on capturing 'usability properties' in discrete mathematical models. We propose notations for describing systems in a 'requirements' style and a 'specification' style. The requirements style is based on a simple temporal logic and the specification style is based on Lamport's Temporal Logic of Actions (TLA) [74]. System functionality is specified as a collection of 'reactions', the temporal composition of which define the behaviour of the system. By observing and analysing interactions it is possible to determine how 'well' a user performs a given task. We argue that a 'usable' system is one that encourages users to perform their tasks efficiently (i.e. to consistently perform their tasks well) hence a system in which users perform their tasks well in a consistent manner is likely to be a usable system. The use of a given functionality linked with different user interfaces then gives a means by which interfaces (and other aspects) can be compared and suggests how they might be harnessed to bias system use so as to encourage the desired user behaviour. Normalising across different users anq different tasks moves us away from the discrete nature of reactions and hence to comfortably describe the use of a system we employ probabilistic rather than discrete mathematics. We illustrate that framework with worked examples and propose an agenda for further work.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

36

Gorton, Ian. „Behavioural specification and simulation of minimum configuration computer systems“. Thesis, Sheffield Hallam University, 1988. http://shura.shu.ac.uk/19708/.

Der volle Inhalt der Quelle

Annotation:

The ultimate goal of Computer-Aided Design research in the area of digital circuits is the automatic synthesis of a complete solution from a behavioural specification. This thesis describes an attempt to attain this ideal in the more limited realm of designing single-board control systems, constructed from general-purpose microprocessor components. The difficulties currently encountered in designing and implementing microprocessor control systems are outlined, and the architecture of an integrated, knowledge-based design system is proposed as a method of overcoming these difficulties. The design system encompasses both behavioural and structural design functions. However, only the tools and techniques required to fulfil the behavioural design functions are considered in detail in this project. A review of previous work in the field of automated digital circuit design and software and hardware specification languages is presented. The major features of a novel language for specifying and simulating control system behaviour are then described, together with an intermediate design description notation, which facilitates the generation of microprocessor assembly language code directly from behavioural specifications. The design and implementation of a fast, generalised microprocessor simulation facility constructed from transputers is discussed, and its performance potential analysed. The simulation facility enables the complete design for a given application to be tested, before any actual hardware construction takes place. Finally, an evaluation of the behavioural specification, synthesis and simulation techniques developed in this project is presented, and the benefits perceived from adopting such techniques are summarised. Issues concerning the integration of these techniques with the knowledge-based structural design tools are also dealt with, and suggestions for further developments and enhancements are identified.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

37

Knapp, James Robert. „Specification for Visual Requirements of Work-Centered Software Systems“. Wright State University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=wright1165518140.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

38

Glower, Jacob Sean. „On the specification of adaptation rates in MRAC systems /“. The Ohio State University, 1988. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487592050228007.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

39

Carr, Hugo P. I. „Executable specification of adaptive open norm-governed computational systems“. Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/9517.

Der volle Inhalt der Quelle

Annotation:

Ad hoc networks may be characterised as volatile systems of agents which collaborate to achieve a common goal, be that the fair use of a common pool resource, the minimisation of packet collisions or efficient data routing. Early approaches to these problems take inspiration from emergent systems, characterised in terms of a population governed by a fixed specification, and out of which arises a relatively sophisticated set of global properties. However, the features of open ad hoc networks necessitate an approach in which participating agents agree to conform to a mutable set of rules (permissions, powers and obligations), which are conventionally rather than physically binding. We are concerned with the development of open agent societies, in which a heterogeneous set of norm-aware agents with conflicting goals can produce similar emergent global properties by introspectively modelling system change. In this thesis we present norm-governed systems spaces, in which the `organised adaptation' of a specification is defined in terms of a finite number of adaptations and environmental states. These two elements are unified in a statistical framework which models an agent's motivation for system change as a set of Markov chains, mapped to a representation of utility. This arrangement allows participants to calculate the total expected utility of any deterministic adaptation strategy, wherein policy changes are chosen for the complete set of environmental fluctuations. We demonstrate this architecture in Matlab with a resource allocation example, in the context of which a norm-governed systems space is trained. Analytic models of agent societies are often idealised, and must be deployed in an experimental test bed to ensure the assumptions remain valid. We present the novel platform PreSage-NGS which constitutes a subsumption of the norm-governed systems space framework into a multi agent system simulation environment. We illustrate an application of this software in the same resource allocation scenario, identifying agent goal conflicts by inferring the alignment of private utility models through the evaluation of publicly expressed strategy proposals. This thesis explores how norm-governed systems spaces may be rapidly trained using lightweight approximations of agent populations in Matlab, which may be verified experimentally to ensure predictions translate to the reality of an open agent society. PreSage-NGS represents a means of exploring the strength of social models for system change in agent societies, in which bounded rationality may create unforeseen interaction dynamics.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

40

Vitalis, Tania. „Development of monoaminergic systems : morphogenetic roles and early specification“. Thesis, University of Edinburgh, 2001. http://hdl.handle.net/1842/23235.

Der volle Inhalt der Quelle

Annotation:

Serotonin is often regarded as a powerful morphogen, however proofs of its action are often missing. In my thesis, I demonstrated that a transient excess of serotonin created pharmacologically by inhibition of the MAOA enzyme altered the formation of barrels of both thalamocortical axons and granular neurons in the layer IV of the developing somatosensory cortex. Thalamocortical axon alterations are characterised by a state of exuberance. A small family of molecules, neurotrophins, has been shown to control early events in the developing thalamus and cortex such as cell survival, neurite outgrowth, migration, or dendritic and axonal morphologies. I showed that trkB, an essential neurotrophin receptor, was expressed in the cortex during the critical period of serotonin sensitivity. Analysis of mice lacking trkB showed subtle alterations in the thalamocortical projections, suggesting that trkB is not essential in the establishment of the barrel field. By obtaining mice lacking MAOA and trkB, I showed a synergistically altered phenotype in the thalamocortical projection, suggesting that in normal conditions serotonin and trkB signalling act synergically in the refinement of the somatosensory thalamocortical map. I also studied the spatio-temporal pattern of MAOA and MAOB and showed striking features during early development: MAOA is tightly linked to the serotoninergic and catecholaminergic phenotypes and MAOB is tightly linked to the glial cell lineage. Analysis of mice lacking Pax6 showed that Pax6 was not essential to monoaminergic development but this study revealed that Netrin-1 was potentially important to the axonal pathfinding of dopaminergic neurons. Analysis of mice lacking Netrin-1 or it receptor deleted in colorectal cancer (DCC) confirmed that Netrin-1 is important but not essential for the axonal guidance of subsets of dopaminergic neurons. More interestingly, this study revealed that the interaction between Netrin-1 and DCC could be important for the cell survival of developing dopaminergic neurons.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

41

Boumezbeur, Rezki. „Design, specification, and validation of telephony systems in LOTOS“. Thesis, University of Ottawa (Canada), 1991. http://hdl.handle.net/10393/7932.

Der volle Inhalt der Quelle

Annotation:

LOTOS (Language Of Temporal Ordering Specification) is a Formal Description Technique (FDT) based on the temporal ordering of observational behaviour. It was developed by ISO (International Organization for Standardization) for the specification of OSI (Open Systems Interconnection) services and protocols. The topic of this thesis is first to present a Sample Telephone System, then formalize it using the FDT language LOTOS. The resulting LOTOS specification is then validated using an interpreter. Testing the design of the specification is also discussed. The thesis is structured as follows: in Chapter 1, we present an introduction to formal description techniques along with a review of some relevant existing work and the objective of this thesis. The next Chapter gives an overview of the LOTOS language. In Chapter 3, we discuss concepts of design of telecommunication systems. The Chapter includes an overview of telecommunication systems along with an informal description of a Sample Telephone System. In Chapter 4, we discuss the formal description in LOTOS of the Sample Telephone System presented in Chapter 3. Validation and testing of the specification are also part of Chapter 3. The conclusions of the thesis along with a discussion of possible future work follow in Chapter 5. Appendix A presents some technical abbreviations, and the Sample Telephone Specification is presented in Appendix B. In Appendix C, we present a set of test processes used to test the Sample Telephone Specification. Finally, some important symbolic trees of processes are presented in Appendix D.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

42

Martin, Patrick J. „Motion description languages: from specification to execution“. Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33860.

Der volle Inhalt der Quelle

Annotation:

Many emerging controls applications have seen increased operational complexity due to the deployment of embedded, networked systems that must interact with the physical environment. In order to manage this complexity, we design different control modes for each system and use motion description languages (MDL) to specify a sequence of these controllers to execute at run-time. Unfortunately, current MDL frameworks lose some of the important details (i.e. power, spatial, or communication capabilities) that affect the execution of the control modes. This work presents several computational tools that work towards closing MDL's specification-to-execution gap, which can result in undesirable behavior of complex systems at run-time. First, we develop the notion of an MDL compiler for control specifications with spatial, energy, and temporal constraints. We define a new MDL for networked systems and develop an algorithm that automatically generates a supervisor to prevent incorrect execution of the multi-agent MDL program. Additionally, we derive conditions for checking if an MDL program satisfies actuator constraints and develop an algorithm to insert new control modes that maintain actuator bounds during the execution of the MDL program. Finally, we design and implement a software architecture that facilitates the development of control applications for systems with power, actuator, sensing, and communication constraints.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

43

Tibbitt-Eggleton, Robert. „Runtime user interface specification using direct manipulation“. Thesis, Staffordshire University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387301.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

44

Scales, William James. „The formal specification of a safety kernal“. Thesis, University of Warwick, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339831.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

45

Jih, Wen-Jang. „Impact of Query Specification Mode and Problem Complexity on Query Specification Productivity of Novice Users of Database Systems“. Thesis, North Texas State University, 1985. https://digital.library.unt.edu/ark:/67531/metadc331056/.

Der volle Inhalt der Quelle

Annotation:

With the increased demand for the utilization of computerized information systems by business users, the need for investigating the impact of various user interfaces has been well recognized. It is usually assumed that providing the user with assistance in the usage o-f a system would significantly increase the user's productivity. There is, however, a dearth of systematic inquiry into this commonly held notion to verify its validity in a scientific fashion. The purpose of this study is to investigate the impact of system-provided user assistance and complexity level of the problem on novice users' productivity in specifying database queries. The study is theoretical in the sense that it presents an approach adopted from research in deductive database systems to attack problems concerning user interface design. It is empirical in that it conducts an experiment in a controlled laboratory setting to collect primary data for the testing of a series of hypotheses. The two independent variables are system-provided user assistance and problem complexity, while the dependent variable is the user's query specification productivity. Three measures are used as separate indicators of query specification productivity: number of syntactic errors, number of semantic errors, and time required for completing a query task. Due to the lack of a well-defined metric for user assistance, the study first presents a generic classification scheme for relational query specification. Based on this classification scheme, two quantitative metrics for measuring the amount of user assistance in terms of prompts and defaults were developed. The user assistance is operationally defined with these two metrics. Four findings emerge as significant results of the study. First, user assistance has a significant main effect on all of the three dependent measures at the 1 percent significance level. Second, problem complexity also has a significant impact on the three productivity measures at the 1 percent significance level. Third, the interaction effect of user assistance and problem complexity on the number of semantic errors and the amount of time for completion is significant at the 1 percent level. Fourth, Although this interaction effect on the number of syntactic errors is not significant at the 5 percent level, it is at the 10 percent level. More research is needed to permit a thorough understanding of the issue of user interface design. A list of topics is suggested for future research to confirm or to modify the findings of this study.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

46

Bicer, Veli. „Architecture Specification Of Service-oriented Systems Through Semantic Web Technologies“. Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608692/index.pdf.

Der volle Inhalt der Quelle

Annotation:

This thesis presents a semantic-based modeling approach for describing Service-Oriented Architectures (SOA). Ontologies are utilized as a major representation mechanism for describing various elements available in the architecture. The methodology proposes an architecture specification mechanism to constuct a unified ontology that enables transition from design concerns to the modeling elements. A multi-level modeling is also achieved by employing Model-Driven Engineering (MDE) techniques to describe various models at different stages of the software architecture. This aims to organize service-oriented models within a number of architecture viewpoints in order to provide an architectural perspective for SOA. The use of ontologies for model specification also allows us to make use of ontology mapping to specify the transformation between different models. Additionally, we present a case study to demonstrate the proposed methodology on a real-world healthcare scenario.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

47

Wittke, Hartmut. „An environment for compositional specification verification of complex embedded systems“. [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=981449689.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

48

Santamaría, Barnadas Eduard. „Formal mission specification and execution mechanisms for unmanned aircraft systems“. Doctoral thesis, Universitat Politècnica de Catalunya, 2010. http://hdl.handle.net/10803/6020.

Der volle Inhalt der Quelle

Annotation:

Unmanned Aircraft Systems (UAS) are rapidly gaining attention due to the increasing potential of their applications in the civil domain. UAS can provide great value performing environmental applications, during emergency situations, as monitoring and surveillance tools, and operating as communication relays among other uses. In general, they are specially well suited for the so-called D-cube operations (Dirty, Dull or Dangerous).
Most current commercial solutions, if not remotely piloted, rely on waypoint based flight control systems for their navigation and are unable to coordinate UAS flight with payload operation. Therefore, automation capabilities and the ability for the system to operate in an autonomous manner are very limited. Some motivators that turn autonomy into an important requirement include limited bandwidth, limits on long-term attention spans of human operators, faster access to sensed data, which also results in better reaction times, as well as benefits derived from reducing operators workload and training requirements.
Other important requirements we believe are key to the success of UAS in the civil domain are reconfigurability and cost-effectiveness. As a result, an affordable platform should be able to operate in different application scenarios with reduced human intervention.
To increase capabilities of UAS and satisfy the aforementioned requirements, we propose adding flight plan and mission management layers on top of a commercial off-the-shelf flight control system. By doing so, a high level of autonomy can be achieved while taking advantage of available technologies and avoiding huge investments. Reconfiguration is made possible by separating flight and mission execution from its specification.
The flight and mission management components presented in this thesis integrate into a wider hardware/software architecture being developed by the ICARUS research group.
This architecture follows a service oriented approach where UAS subsystems are connected together through a common networking infrastructure. Components can be added and removed from the network in order to adapt the system to the target mission.
The first contribution of this thesis consists, then, in a flight specification language that enables the description of the flight plan in terms of legs. Legs provide a higher level of abstraction compared to plain waypoints since they not only specify a destination but also the trajectory that should be followed to reach it. This leg concept is extended with additional constructs that enable specification of alternative routes, repetition and generation of complex trajectories from a reduced number of parameters.
A Flight Plan Manager (FPM) service has been developed that is responsible for the execution of the flight plan. Since the underlying flight control system is still waypoint based, additional intermediate waypoints are automatically generated to adjust the flight to the desired trajectory.
In order to coordinate UAS flight and payload operation a Mission Manager (MMa) service has also been developed. The MMa is able to adapt payload operation according to the current flight phase, but it can also act on the FPM and make modifications on the flight plan for a better adaption to the mission needs. To specify UAS behavior, instead of designing a new language, we propose using an in-development standard for the specification of state machines called State Chart XML.
Finally, validation of the proposed specification and execution elements is carried out with two example missions executed in a simulation environment. The first mission mimics the procedures required for inspecting navigation aids and shows the UAS performance in a complex flight scenario. In this mission only the FPM is involved. The second example combines operation of the FPM with the MMa. In this case the mission consists in the detection of hotspots on a given area after a hypothetical wildfire. This second simulation shows how the MMa is able to modify the flight plan in order to adapt the trajectory to the mission needs. In particular, an eight pattern is flown over each of the dynamically detected potential hot spots.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

49

Zhang, Lihong. „Managing the specification process in complex product and systems projects“. Thesis, University of Brighton, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408750.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

50

Paterno, Fabio Domenico. „A method for formal specification and verification of interactive systems“. Thesis, University of York, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297141.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Dissertationen zum Thema „Specification of cyberphysical systems“

Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an