62 research outputs found
Automated Formal Analysis of Temporal Properties of Ladder Programs
International audienceProgrammable Logic Controllers are industrial digital computers used as automation controllers in manufacturing processes. The Ladder language is a programming language used to develop software for such controllers. In this work, we consider the description of the expected behaviour of a Ladder program under the form of a timing chart, describing a scenario of execution. Our aim is to prove that the given Ladder program conforms to the expected temporal behaviour given by such a timing chart. Our approach amounts to translating the Ladder code, together with the timing chart, into a program for the Why3 environment for deductive program verification. The verification proceeds with the generation of verification conditions: mathematical formulas to be checked valid using automated theorem provers. The ultimate goal is twofold. On the one hand, by obtaining a complete proof, one verifies the conformity of the Ladder code with respect to the timing chart with a high degree of confidence. On the other hand, in the case the proof is not fully completed, one obtains a counterexample, illustrating a possible execution scenario of the Ladder code which does not conform to the timing chart
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Transiently Powered Computers
Demand for compact, easily deployable, energy-efficient computers has driven the development of general-purpose transiently powered computers (TPCs) that lack both batteries and wired power, operating exclusively on energy harvested from their surroundings.
TPCs\u27 dependence solely on transient, harvested power offers several important design-time benefits. For example, omitting batteries saves board space and weight while obviating the need to make devices physically accessible for maintenance. However, transient power may provide an unpredictable supply of energy that makes operation difficult. A predictable energy supply is a key abstraction underlying most electronic designs. TPCs discard this abstraction in favor of opportunistic computation that takes advantage of available resources. A crucial question is how should a software-controlled computing device operate if it depends completely on external entities for power and other resources? The question poses challenges for computation, communication, storage, and other aspects of TPC design.
The main idea of this work is that software techniques can make energy harvesting a practicable form of power supply for electronic devices. Its overarching goal is to facilitate the design and operation of usable TPCs.
This thesis poses a set of challenges that are fundamental to TPCs, then pairs these challenges with approaches that use software techniques to address them. To address the challenge of computing steadily on harvested power, it describes Mementos, an energy-aware state-checkpointing system for TPCs. To address the dependence of opportunistic RF-harvesting TPCs on potentially untrustworthy RFID readers, it describes CCCP, a protocol and system for safely outsourcing data storage to RFID readers that may attempt to tamper with data. Additionally, it describes a simulator that facilitates experimentation with the TPC model, and a prototype computational RFID that implements the TPC model.
To show that TPCs can improve existing electronic devices, this thesis describes applications of TPCs to implantable medical devices (IMDs), a challenging design space in which some battery-constrained devices completely lack protection against radio-based attacks. TPCs can provide security and privacy benefits to IMDs by, for instance, cryptographically authenticating other devices that want to communicate with the IMD before allowing the IMD to use any of its battery power. This thesis describes a simplified IMD that lacks its own radio, saving precious battery energy and therefore size. The simplified IMD instead depends on an RFID-scale TPC for all of its communication functions.
TPCs are a natural area of exploration for future electronic design, given the parallel trends of energy harvesting and miniaturization. This work aims to establish and evaluate basic principles by which TPCs can operate
NASA Tech Briefs, April 1995
This issue of the NASA Tech Briefs has a special focus section on video and imaging, a feature on the NASA invention of the year, and a resource report on the Dryden Flight Research Center. The issue also contains articles on electronic components and circuits, electronic systems, physical sciences, materials, computer programs, mechanics, machinery, manufacturing/fabrication, mathematics and information sciences and life sciences. In addition to the standard articles in the NASA Tech brief, this contains a supplement entitled "Laser Tech Briefs" which features an article on the National Ignition Facility, and other articles on the use of Lasers
Personality Identification from Social Media Using Deep Learning: A Review
Social media helps in sharing of ideas and information among people scattered around the world and thus helps in creating communities, groups, and virtual networks. Identification of personality is significant in many types of applications such as in detecting the mental state or character of a person, predicting job satisfaction, professional and personal relationship success, in recommendation systems. Personality is also an important factor to determine individual variation in thoughts, feelings, and conduct systems. According to the survey of Global social media research in 2018, approximately 3.196 billion social media users are in worldwide. The numbers are estimated to grow rapidly further with the use of mobile smart devices and advancement in technology. Support vector machine (SVM), Naive Bayes (NB), Multilayer perceptron neural network, and convolutional neural network (CNN) are some of the machine learning techniques used for personality identification in the literature review. This paper presents various studies conducted in identifying the personality of social media users with the help of machine learning approaches and the recent studies that targeted to predict the personality of online social media (OSM) users are reviewed
Undergraduate and Graduate Course Descriptions, 2013 Summer
Wright State University undergraduate and graduate course descriptions from Summer 2013
Undergraduate and Graduate Course Descriptions, 2013 Summer
Wright State University undergraduate and graduate course descriptions from Summer 2013
Student Expectations: The effect of student background and experience
CONTEXT
The perspectives and previous experiences that students bring to their programs of study can affect their approaches to study and the depth of learning that they achieve Prosser & Trigwell, 1999; Ramsden, 2003). Graduate outcomes assume the attainment of welldeveloped independent learning skills which can be transferred to the work-place.
PURPOSE
This 5-year longitudinal study investigates factors influencing students’ approaches to learning in the fields of Engineering, Software Engineering, and Computer Science, at two higher education institutes delivering programs of various levels in Australia and New Zealand. The study aims to track the development of student approaches to learning as they progress through their program. Through increased understanding of students’ approaches, faculty will be better able to design teaching and learning strategies to meet the needs of an increasingly diverse student body. This paper reports on the first stage of the project.
APPROACH
In August 2017, we ran a pilot of our survey using the Revised Study Process Questionnaire(Biggs, Kember, & Leung, 2001) and including some additional questions related to student demographics and motivation for undertaking their current program of study. Data were analysed to evaluate the usefulness of data collected and to understand the demographics of the student cohort. Over the period of the research, data will be collected using the questionnaire and through focus groups and interviews.
RESULTS
Participants provided a representative sample, and the data collected was reasonable, allowing the questionnaire design to be confirmed.
CONCLUSIONS
At this preliminary stage, the study has provided insight into the student demographics at both institutes and identified aspects of students’ modes of engagement with learning. Some areas for improvement of the questionnaire have been identified, which will be implemented for the main body of the study
Sécurité et protection de la vie privée dans les systèmes embarqués automobiles
Electronic equipment has become an integral part of a vehicle's network architecture, which consists of multiple buses and microcontrollers called Electronic Control Units (ECUs). These ECUs recently also connect to the outside world. Navigation and entertainment system, consumer devices, and Car2X functions are examples for this. Recent security analyses have shown severe vulnerabilities of exposed ECUs and protocols, which may make it possible for attackers to gain control over a vehicle. Given that car safety-critical systems can no longer be fully isolated from such third party devices and infotainment services, we propose a new approach to securing vehicular on-board systems that combines mechanisms at different layers of the communication stack and of the execution platforms. We describe our secure communication protocols, which are designed to provide strong cryptographic assurances together with an efficient implementation fitting the prevalent vehicular communication paradigms. They rely on hardware security modules providing secure storage and acting as root of trust. A distributed data flow tracking based approach is employed for checking code execution against a security policy describing authorized communication patterns. Binary instrumentation is used to track data flows throughout execution (taint engine) and also between control units (middleware), thus making it applicable to industrial applications. We evaluate the feasibility of our mechanisms to secure communication on the CAN bus, which is ubiquitously implemented in cars today. A proof of concept demonstrator also shows the feasibility of integrating security features into real vehicles.L'équipement électronique de bord est maintenant devenue partie intégrante de l'architecture réseau des véhicules. Elle s’appuie sur l'interconnexion de microcontroleurs appelés ECUs par des bus divers. On commence maintenant à connecter ces ECUs au monde extérieur, comme le montrent les systèmes de navigation, de divertissement, ou de communication mobile embarqués, et les fonctionnalités Car2X. Des analyses récentes ont montré de graves vulnérabilités des ECUs et protocoles employés qui permettent à un attaquant de prendre le contrôle du véhicule. Comme les systèmes critiques du véhicule ne peuvent plus être complètement isolés, nous proposons une nouvelle approche pour sécuriser l'informatique embarquée combinant des mécanismes à différents niveaux de la pile protocolaire comme des environnements d'exécution. Nous décrivons nos protocoles sécurisés qui s'appuient sur une cryptographie efficace et intégrée au paradigme de communication dominant dans l'automobile et sur des modules de sécurité matériels fournissant un stockage sécurisé et un noyau de confiance. Nous décrivons aussi comment surveiller les flux d'information distribués dans le véhicule pour assurer une exécution conforme à la politique de sécurité des communications. L'instrumentation binaire du code, nécessaire pour l’industrialisation, est utilisée pour réaliser cette surveillance durant l’exécution (par data tainting) et entre ECUs (dans l’intergiciel). Nous évaluons la faisabilité de nos mécanismes pour sécuriser la communication sur le bus CAN aujourd'hui omniprésent dans les véhicules. Une preuve de concept montre aussi la faisabilité d'intégrer des mécanismes de sécurité dans des véhicules réels
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