A particle filtering approach for joint detection/estimation of multipath effects on GPS measurements

Multipath propagation causes major impairments to Global Positioning System (GPS) based navigation. Multipath results in biased GPS measurements, hence inaccurate position estimates. In this work, multipath effects are considered as abrupt changes affecting the navigation system. A multiple model formulation is proposed whereby the changes are represented by a discrete valued process. The detection of the errors induced by multipath is handled by a Rao-Blackwellized particle filter (RBPF). The RBPF estimates the indicator process jointly with the navigation states and multipath biases. The interest of this approach is its ability to integrate a priori constraints about the propagation environment. The detection is improved by using information from near future GPS measurements at the particle filter (PF) sampling step. A computationally modest delayed sampling is developed, which is based on a minimal duration assumption for multipath effects. Finally, the standard PF resampling stage is modified to include an hypothesis test based decision step

A rao-blackwellized particle filter for INS/GPS integration

The localization performance of a navigation system can be improved by coupling different types of sensors. This paper focuses on INS-GPS integration. INS and GPS measurements allow to dene a non-linear state space model, which is appropriate to particle ltering. This model being conditionally linear Gaussian, a Rao-Blackwellization procedure can be applied to reduce the variance of the estimates

TIC et prise en charge des personnes handicapées mentales

International audienceL’utilisation de l’informatique et de l’Internet par les personnes handicapées mentales accueillies en établissements spécialisés s’inscrit aujourd’hui dans les pratiques professionnelles du champ médico-social. Si cette communication médiatisée devient un relais de la prise en charge, elle équipe et valorise une professionnalité, mais participe aussi d’une évolution des représentations des professionnels sur les usagers de ces établissements

DIGITAL FORENSIC READINESS FRAMEWORK BASED ON HONEYPOT AND HONEYNET FOR BYOD

The utilization of the internet within organizations has surged over the past decade. Though, it has numerous benefits, the internet also comes with its own challenges such as intrusions and threats. Bring Your Own Device (BYOD) as a growing trend among organizations allow employees to connect their portable devices such as smart phones, tablets, laptops, to the organization’s network to perform organizational duties. It has gained popularity over the years because of its flexibility and cost effectiveness. This adoption of BYOD has exposed organizations to security risks and demands proactive measures to mitigate such incidents. In this study, we propose a Digital Forensic Readiness (DFR) framework for BYOD using honeypot technology. The framework consists of the following components: BYOD devices, Management, People, Technology and DFR. It is designed to comply with ISO/IEC 27043, detect security incidents/threats and collect potential digital evidence using low- and high-level interaction honeypots. Besides, the framework proffers adequate security support to the organization through space isolation, device management, crypto operations, and policies database. This framework would ensure and improve information security as well as securely preserve digital evidence. Embedding DFR into BYOD will improve security and enable an organization to stay abreast when handling a security incident

Effect of carboxymethylcellulose on potassium bitartrate crystallization on model solution and white wine

Instability in bottled wines refer to tartaric salts crystallization such as potassium bitartrate (KHT). It is not desirable as consumers see the settled salts as an evidence of a poor quality control. In some cases, it causes excessive gushing in sparkling wine. We investigate the effect of two oenological carboxymethylcellulose (CMC) for KHT inhibition in a model solution of white wine by studying the impact of some properties of CMC such as the degree of polymerization, the degree of substitution, and the apparent dissociation constant determined by potentiometric titration. Polyelectrolyte adsorption is used for determining the surface and total charge and for providing information about the availability of CMC charged groups for interacting with KHT crystal faces. The inhibitory efficiency of CMC on model solution is evaluated by measuring the induction time with the help of conductimetric methods. Crystals growth with and without CMC are studied by observation with MEB and by thermal analysis using DSC. The results confirm the effectiveness of CMC as an inhibitor of KHT crystallization in a model solution. The main hypothesis of the mechanism lies in the interaction of dissociated anionic carboxymethyl groups along the cellulose backbone with positively charged layers on KHT faces like the {0 1 0} face. Key factors such as pH, CMC chain length and total charge are discusse

Today's Learner, Preferences In Teaching Techniques

The computer age is here. Students are tuned in to the latest digital devices and methods available today. Most students are exposed to short messages with video enhancements. This gives rise to a student who gets frustrated and bored with the standard lecture technique of years past. To achieve a greater effectiveness and learning outcome in delivering a lecture and subsequent learning, the professor has to know and understand the changes that are occurring in today’s learner. This paper presents findings of a study comparing the perceptions of first year freshmen business students’ with upper class business students’ perceptions as to how learning and assessment should occur in the classroom. The study also evaluates the differences between the various types of business majors