Vulnerability analysis of satellite-based synchronized smart grids monitoring systems

The large-scale deployment of wide-area monitoring systems could play a strategic role in supporting the evolution of traditional power systems toward smarter and self-healing grids. The correct operation of these synchronized monitoring systems requires a common and accurate timing reference usually provided by a satellite-based global positioning system. Although these satellites signals provide timing accuracy that easily exceeds the needs of the power industry, they are extremely vulnerable to radio frequency interference. Consequently, a comprehensive analysis aimed at identifying their potential vulnerabilities is of paramount importance for correct and safe wide-area monitoring system operation. Armed with such a vision, this article presents and discusses the results of an experimental analysis aimed at characterizing the vulnerability of global positioning system based wide-area monitoring systems to external interferences. The article outlines the potential strategies that could be adopted to protect global positioning system receivers from external cyber-attacks and proposes decentralized defense strategies based on self-organizing sensor networks aimed at assuring correct time synchronization in the presence of external attacks

INFLUENCE DU TRAITEMENT THERMIQUE ET MECANIQUE SUR LES PROPRIETES MECANIQUES ET STRUCTURALES DES ACIERS AU MANGANESE MOULES.

Molded Steel with manganese have approximately 1,2% C and 12% Mn, this high proportion of manganese gives to this alloy a stable austenitic structure on a room temperature. The experimental methods used for metallurgical studies are spark optical emission spectroscopy, optical microscopy, scanning electron microscopy, micro-hardness and hardnesss test. Steel 1 is heat-treated constitued by 15,516 % of manganese, 2,677 % of chromuim and 1,286 % of carbon. Steel 2 is mechanically treated contains 13,454 % of manganese, 1,721 % of chromuim and 1,213 % of carbon . Steel 1 has sustained quench at 1070°C, for two differents maintaining times on oven 30 and 50 minutes for a thickness of 150 millimeters then for two differents thickness 100 and 150 millimeters for a time of 50 minutes. When maintaining time on the oven increase for low dimension, surface’s alloy become more ductile. We have applied a mechanical treatement manually on steel 2 surface, his hardness increase significantly

Verification and Control of Partially Observable Probabilistic Real-Time Systems

We propose automated techniques for the verification and control of probabilistic real-time systems that are only partially observable. To formally model such systems, we define an extension of probabilistic timed automata in which local states are partially visible to an observer or controller. We give a probabilistic temporal logic that can express a range of quantitative properties of these models, relating to the probability of an event's occurrence or the expected value of a reward measure. We then propose techniques to either verify that such a property holds or to synthesise a controller for the model which makes it true. Our approach is based on an integer discretisation of the model's dense-time behaviour and a grid-based abstraction of the uncountable belief space induced by partial observability. The latter is necessarily approximate since the underlying problem is undecidable, however we show how both lower and upper bounds on numerical results can be generated. We illustrate the effectiveness of the approach by implementing it in the PRISM model checker and applying it to several case studies, from the domains of computer security and task scheduling

Steady improvement of infection control services in six community hospitals in Makkah following annual audits during Hajj for four consecutive years

BACKGROUND: the objective of this study was to evaluate the impact of annual review of the infection control practice in all Ministry of Health hospitals in the holy city of Makkah, Saudi Arabia, during the Hajj period of four lunar Islamic years, 1423 to 1426 corresponding to 2003 to 2006. METHODS: audit of infection control service was conducted annually over a 10-day period in six community hospitals with bed capacities ranging from 140 to 557 beds. Data were collected on standardized checklists on various infection control service items during surprise visits to the medical, pediatric, surgical, and critical care units, and the kitchens. Percentage scores were calculated for audited items. The results of the audit for hospitals were confidentially sent to them within four weeks after the end of Hajj. RESULTS: deficiencies observed in the first audit included lack of infection control committees, infection control units, infection control educational activities, and surveillance system and shortage of staff. These deficiencies were resolved in the subsequent audits. The average (range) scores of hospitals in 11 infection control items increased from 43% (20–67%) in the first audit to 78% (61–93%) in the fourth audit. CONCLUSION: regular hospital infection control audits lead to significant improvement of infection control practice. There is a need to build a rigorous infection control audit into hospitals' ongoing monitoring and reporting to the Ministry of Health and to provide these hospitals with feed back on such audits to continuously strengthen the safety standards for patients, visitors, and employees

MODELISATION DE L'INFLUENCE DU TRAITEMENT THERMIQUE SUR LES PROPRIETES MECANIQUES DES ALLIAGES ALUMINIUM-CUIVRE (Al-Cu)

In order to master and improve the quality and properties of the final products, the major industrial challenge lies in the possibility of controlling the morphology, size of microstructures that reside within the molded pieces, as well as their defects; this is the fundamental reason according to which we are more and more interested in mastering the growth and germination of such alloys, as well as the developing structures, at the time of solidification process. The modeling reveals as a valuable aid in the mastery of the formation of such heterogeneousness: segregation cells that are incompatible with industrial requirements. The whole work focuses upon the modeling of the segregation phenomenon of the four hypoeutectic alloys, Al1%Cu, Al2%Cu, Al3%Cu et Al4%Cu, as well as the copper effect upon certain mechanical properties of aluminum. Usually, the microstructure and mechanical behavior of such alloys as Al-Cu are directly influenced by some parameters such as composition, cooling velocity and homogenization process

Yrast Band Description of 150Sm, 152Sm, 154Gd and 192Os Nuclei Using VAVMNS Model

In the frame work of the concept of softness parameter ? of nucle

Analgesic and sedative effects of caudal epidural tramadol in dromedary camels

This study aimed to investigate the analgesic efficacy of caudal epidural administration of tramadol in dromedary camels (Camelus dromedarius). A total of 10 dromedary camels of both sexes were se-lected and randomly assigned to one of two groups to receive epidurally either 1 mg/kg or 2 mg/kg of tramadol hydrochloride. The injections were made into the epidural space at first intercoccygeal junc-tion. Using a pinprick method, analgesia was tested. Duration and onset of complete perineal analge-sia were determined. Ataxia and sedation were also assessed and recorded. Clinical parameters in-cluding heart rate, respiratory rate and rectal temperature were measured. The lower dose (1 mg/kg) of tramadol induced analgesia only in the tail but the higher dose produced complete antinociception in the tail, anus and perineum. Analgesia of the hind limbs was not achieved after either doses of tramadol. The mean times to onset and duration of complete analgesia in camels receiving epidural tramadol at a dose of 2 mg/kg were 22±2.55 min and 65±8.66 min, respectively. Various degrees of ataxia occurred in all camels. Mild to deep sedation was observed following both doses. Mean heart rate, respiratory rate, and rectal temperature tended to increase for the first 15 or 30 min after injec-tion. Based on the results of this study, analgesic effects of caudal epidural tramadol were dose de-pendent. Epidural tramadol at a dose of 2 mg/kg would provide suitable postoperative analgesia for various manipulations in the tail, anus and perineum in standing dromedary camels

Parameter-Independent Strategies for pMDPs via POMDPs

Markov Decision Processes (MDPs) are a popular class of models suitable for solving control decision problems in probabilistic reactive systems. We consider parametric MDPs (pMDPs) that include parameters in some of the transition probabilities to account for stochastic uncertainties of the environment such as noise or input disturbances. We study pMDPs with reachability objectives where the parameter values are unknown and impossible to measure directly during execution, but there is a probability distribution known over the parameter values. We study for the first time computing parameter-independent strategies that are expectation optimal, i.e., optimize the expected reachability probability under the probability distribution over the parameters. We present an encoding of our problem to partially observable MDPs (POMDPs), i.e., a reduction of our problem to computing optimal strategies in POMDPs. We evaluate our method experimentally on several benchmarks: a motivating (repeated) learner model; a series of benchmarks of varying configurations of a robot moving on a grid; and a consensus protocol.Comment: Extended version of a QEST 2018 pape