Improved Accuracy in Predicting the Best Sensor Fusion Architecture for Multiple Domains

Multi-sensor fusion intends to boost the general reliability of a decision-making procedure or allow one sensor to compensate for others’ shortcomings. This field has been so prominent that authors have proposed many different fusion approaches, or “architectures” as we call them when they are structurally different, so it is now challenging to prescribe which one is better for a specific collection of sensors and a particular application environment, other than by trial and error. We propose an approach capable of predicting the best fusion architecture (from predefined options) for a given dataset. This method involves the construction of a meta-dataset where statistical characteristics from the original dataset are extracted. One challenge is that each dataset has a different number of variables (columns). Previous work took the principal component analysis’s first k components to make the meta-dataset columns coherent and trained machine learning classifiers to predict the best fusion architecture. In this paper, we take a new route to build the meta-dataset. We use the Sequential Forward Floating Selection algorithm and a T transform to reduce the features and match them to a given number, respectively. Our findings indicate that our proposed method could improve the accuracy in predicting the best sensor fusion architecture for multiple domains.

Validation of the attitudinal scale of open educational practices in university teachers

The relevance of Open Educational Resources (OER) in the Latin American university context requires an instrument that measures the conceptual, procedural, and attitudinal aspects that teachers consider having in their open educational practices. The purpose of this research is to describe the process of design and validation of the Attitudinal Scale of Open Educational Practices (ASOEP) Scale. Consequently, the methodological approach corresponds to a descriptive, transectional, instrumental design that has three components: scale design, evaluation by expert judgment and validation with the pilot application. The pilot test was applied to a random sample with 123 teachers at a university in Colombia. The results from the validation of the content had the participation of five international experts who were classified according to coefficient K in the range between (k: .80 and k: 1.00). From the pilot application, the ASOEP Scale presented a general reliability of (α: .943). Keywords: Open Educational Practices, Open Educational Resources, Open Education, University teaching, Attitudinal scale

In Vitro Newly Isolated Environmental Phage Activity against Biofilms Preformed by Pseudomonas aeruginosa from Patients with Cystic Fibrosis

As disease worsens in patients with cystic fibrosis (CF), Pseudomonas aeruginosa (PA) colonizes the lungs, causing pulmonary failure and mortality. Progressively, PA forms typical biofilms, and antibiotic treatments determine multidrug-resistant (MDR) PA strains. To advance new therapies against MDR PA, research has reappraised bacteriophages (phages), viruses naturally infecting bacteria. Because few in vitro studies have tested phages on CF PA biofilms, general reliability remains unclear. This study aimed to test in vitro newly isolated environmental phage activity against PA isolates from patients with CF at Bambino Gesù Children’s Hospital (OBG), Rome, Italy. After testing in vitro phage activities, we combined phages with amikacin, meropenem, and tobramycin against CF PA pre-formed biofilms. We also investigated new emerging morphotypes and bacterial regrowth. We obtained 22 newly isolated phages from various environments, including OBG. In about 94% of 32 CF PA isolates tested, these phages showed in vitro PA lysis. Despite poor efficacy against chronic CF PA, five selected-lytic-phages (Φ4_ZP1, Φ9_ZP2, Φ14_OBG, Φ17_OBG, and Φ19_OBG) showed wide host activity. The Φ4_ZP1-meropenem and Φ14_OBG-tobramycin combinations significantly reduced CF PA biofilms (p < 0.001). To advance potential combined phage-antibiotic therapy, we envisage further in vitro test combinations with newly isolated phages, including those from hospital environments, against CF PA biofilms from early and chronic infections.

Technique for assessing the probability of survival of structural members with delaminations

The paper presents a technique of quantitative assessment of probability of failure-free operation of composite structures containing an ensemble of defects in the form of delamination. This method is based on approaches of general reliability theory. The proposed method was validated relative to the assessment of reliability of a composite conical bay with multiple delaminations generated under loads at the stage of inserting the launch vehicle into orbit. The statistical dynamic problem was solved by using Monte Carlo method which was implemented by means of algorithms developed by the author in ANSYS software. Nonlinear analysis of the conical bay buckling was carried out for each implementation. Quantitative assessment of survival probability was conducted on the basis of the hypothesis of the law of Gaussian distribution of load-bearing capacity and using the graphical method of reliability calculation. Good agreement of the results obtained by both methods was noted.

Dependability Aspects in Configurable Embedded Operating Systems

As all conceptual layers in the software stack depend on the operating system (OS) to reliably provide resource-management services and isolation, it can be considered the “reliable computing base” that must be hardened for correct operation under fault models such as transient hardware faults in the memory hierarchy. In this chapter, we approach the problem of system-software hardening in three complementary scenarios. (1) We address the following research question: Where do the general reliability limits of static system-software stacks lie, if designed from scratch with reliability as a first-class design goal? In order to reduce the proverbial “attack surface” as far as possible, we harness static application knowledge from an AUTOSAR-compliant task set, and protect the whole OS kernel with AN-encoding. This static approach yields an extremely reliable software system, but is constrained to specific application domains. (2) We investigate how reliable a dynamic COTS embedded OS can become if hardened with programming-language and compiler-based fault-tolerance techniques. We show that aspect-oriented programming is an appropriate means to encapsulate generic software-implemented hardware fault tolerance mechanisms that can be application-specifically applied to a selection of OS components. (3) We examine how system-software stacks can survive even more adverse fault models like whole-system outages, using emerging persistent memory (PM) technology as a vehicle for state conservation. Our findings include that software transactional memory facilitates maintaining consistent state within PM and allows fast recovery.

Predicting the stability of mutant proteins by computational approaches: an overview

A very large number of computational methods to predict the change in thermodynamic stability of proteins due to mutations have been developed during the last 30 years, and many different web servers are currently available. Nevertheless, most of them suffer from severe drawbacks that decrease their general reliability and, consequently, their applicability to different goals such as protein engineering or the predictions of the effects of mutations in genetic diseases. In this review, we have summarized all the main approaches used to develop these tools, with a survey of the web servers currently available. Moreover, we have also reviewed the different assessments made during the years, in order to allow the reader to check directly the different performances of these tools, to select the one that best fits his/her needs, and to help naïve users in finding the best option for their needs.

On the functional reliability of the regenerative life support systems for manned spacecraft

The paper considers two classes of problems concerned with reliability of manned spacecraft regenerative life-support system (RLSS) on the stages of design, testing and operation, as well as the approach to the definition of “functional reliability” as a component of the general reliability theory as opposed to the “structural reliability”. General methods for calculating the reliability of technological systems at all stages of their life cycle are considered. Mathematical models of functional, structural, and overall reliability of a manned spacecraft RLSS are proposed. Based on the results of independent tests of the carbon dioxide processing system, calculations of the functional reliability of the unit for the hydrogenation of carbon dioxide are performed. The unit is being developed for use in the manned spacecraft RLSS. The article also presents the conclusions on the analysis of the results of the calculation of functional reliability for the carbon dioxide hydrogenation unit.