Rings which are Baer or quasi-Baer modulo a radical

The Baer and the quasi-Baer properties of rings are extended to a module theoretic setting in this chapter. Using the endomorphism ring of a module, the notions of Baer, quasi-Baer, and Rickart modules are introduced and studied. Similar to the fact that every Baer ring is nonsingular, we shall see that every Baer module satisfies a weaker notion of nonsingularity of modules (\(\mathcal{K}\)-nonsingularity) which depends on the endomorphism ring of the module. Strong connections between a Baer module and an extending module will be observed via this weak nonsingularity and its dual notion. It is shown that an extending module which is \(\mathcal{K}\)-nonsingular is precisely a \(\mathcal{K}\)-cononsingular Baer module. This provides a module theoretic analogue of the Chatters-Khuri theorem for rings. Direct summands of Baer and quasi-Baer modules respectively inherit these properties. This provides a rich source of examples of Baer and quasi-Baer modules, since one can readily see that for any (quasi-)Baer ring R and an idempotent e in R, the right R-module eR R is always a (quasi-)Baer module. It will be seen that every projective module over a quasi-Baer ring is a quasi-Baer module. Connections of a (quasi-)Baer module and its endomorphism ring are discussed. Characterizations of classes of rings via the Baer property of certain classes of free modules over them are presented. An application also yields a type theory for \(\mathcal{K}\)-nonsingular extending (continuous) modules which, in particular, improve the type theory for nonsingular injective modules provided by Goodearl and Boyle.

A radical α has the Amitsur property if α(A[x])=(α(A[x])∩A)[x] for all rings A. For rings R⊆S with the same unity, we call S a finite centralizing extension of R if there exist b1,b2,…,bt∈S such that S=b1R+b2R+⋯+btR and bir=rbi for all r∈R and i=1,2,…,t. A radical α is FCE-friendly if α(S)∩R⊆α(R) for any finite centralizing extension S of a ring R. We show that if α is a supernilpotent radical whose semisimple class contains the ring ℤ of all integers and α is FCE-friendly, then α has the Amitsur property. In this way the Amitsur property of many well-known radicals such as the prime radical, the Jacobson radical, the Brown–McCoy radical, the antisimple radical and the Behrens radical can be established. Moreover, applying this condition, we will show that the upper radical 𝒰(*k) generated by the essential cover *k of the class * of all *-rings has the Amitsur property and 𝒰(*k)(A[x])=𝒰(*k)(A)[x], where a semiprime ring R is called a *-ring if the factor ring R/I is prime radical for every nonzero ideal I of R. The importance of *-rings stems from the fact that a *-ring A is Jacobson semisimple if and only if A is a primitive ring.

In this work we present a novel wearable haptic system based on an elastic fabric which can be moved forward and backward over the user forearm thus simulating a human caress. The system allows to control both the velocity of the “caress-like” movement, by regulating motor velocity, and the “strength of the caress”, by regulating motor positions and hence the force exerted by the fabric on the user forearm. Along with a description of the mechanical design and control of the system, we also report the preliminary results of psycho-physiological assessment tests performed by six healthy participants. Such an assessment is intended as a preliminary characterization of the device capability of eliciting tactually emotional states in humans using different combinations of velocity and caress strength. The emotional state is expressed in terms of arousal and valence. Moreover, the activation of the autonomic nervous system is also evaluated through the analysis of the electrodermal response (EDR). The main results reveal a statistically significant correlation between the perceived arousal level and the “strength of the caress” and between the perceived valence level and the “velocity of the caress”. Moreover, we found that phasic EDR is able to discern between pleasant and unpleasant stimuli. These preliminary results are very encouraging and confirm the effectiveness of this device in conveying emotional-like haptic stimuli in a controllable and wearable fashion.

On the Jacobson radical of a groupoid graded ring

We describe the beamforming strategy and the preliminary laboratory characterization results of the beam pattern synthesized by the PHAROS2 Phased Array Feed (PAF), a 4-8 GHz PAF with digital beamformer for radio astronomy application. The PAF is based on an array of 10×11 dual-polarization Vivaldi antennas cryogenically cooled at 20 K along with low noise amplification modules (LNAs) cascaded with a multi-channel Warm Section (WS) receiver. We present the beamforming and test procedures used to, respectively digitally synthesize and characterize the PHAROS2 antenna array beam pattern at 6 GHz. The tests of the array were carried out at room temperature by directly connecting 24 antenna elements to the WS and iTPM digital beamformer in a laboratory measurement setup.

The description of the setup and experimental methodology used to quantify the local mixing of a helium-air mixture with the non-intrusive laser based Filtered Rayleigh Scattering (FRS) technique in a Mach 2.5 vortical flow is presented. Of particular interest is the effect of the imposed vortex dynamics on the degree of mixedness of the two constituent mixture components in the region of the mutually interacting co-rotating vortices generated by a strut injector specifically designed for the study of multiple vortex interactions in supersonic flow. The application of the FRS technique in such highly complex vortical flows, however, is not straightforward. Thus, detailed preliminary experimental characterization of all subsystems of the measurement is required along with a methodical experimental design procedure in order to achieve consistently successful measurements that are meaningful and relevant. All aspects of the experimental design and methodology will be presented, beginning with the necessary theoretical background of the FRS procedure and concluding with the preliminary results and supporting evidence showing the proper design of the mixing experiments.

In this paper an artificial modular system applied to object classification in brain MR images is presented. It consists of two modules based on neural architectures joined in sequence to perform first an image segmentation and then an object classification. For these two steps a Self Organizing Map and a Multilayer Perceptron trained with the Back-Propagation learning rule have been used. The objective of the system is the automatic recognition of the anatomic structures in MR images of the cerebral section passing through the orbits and the visual pathways. To reach this goal we have submitted the two networks to a training phase realized by an unsupervised process for the image segmentation and by a supervised process for regions labelling. This last step has been based on topographic relations supplied by a medical expert. The system has been useful to discriminate 20 different classes of anatomic objects over the considered section. Preliminary results are presented.

A complete low-cost open-source portable ultrasound test bench will be demonstrated for a variety of biomedical imaging applications. The test bench is a programmable 64-channel system with a modular design that can be easily updated with improved hardware and software for research on wearable and implantable medical ultrasound. Initial imaging results on tissue phantoms will be shown. Moreover, a rigid prototype of a novel wearable conformal ultrasound array with integrated imaging and modulation capabilities will be demonstrated. Preliminary measurement and characterization results of the prototype show promising results with ~2.4 MHz bandwidth.

Cathodic arc evaporation of graphite with controlled cathode spot position

A great deal of the interesting information captured by aerial imagery is as yet unused, even though it could help to enrich maps and improve navigation. For this information to be made available, objects such as buildings or roads need to be recognized on images. This is laborious to do entirely manually, but non-trivial to perform computationally. In this paper, we present an automated method for detecting objects of a chosen class (pedestrian crosswalks) on orthophotos, a method which can be adapted for various classes of objects. The method uses a supervised machine-learning approach with a deep convolutional neural network. We re-trained the final layer of a pre-trained neural network using specific imagery and crowdsourced geographic information from the OpenStreetMap (OSM) project. The result is an easily enhanceable and scalable application which is able to search for objects in aerial imagery. We achieved an accuracy of well over 95% for crosswalks and promising preliminary results for roundabouts.

Current object recognition systems aim at recognizing numerous object classes under limited supervision conditions. This paper provides a benchmark for evaluating progress on this fundamental task. Several methods have recently proposed to utilize the commonalities between object classes in order to improve generalization accuracy. Such methods can be termed interclass transfer techniques. However, it is currently difficult to asses which of the proposed methods maximally utilizes the shared structure of related classes. In order to facilitate the development, as well as the assessment of methods for dealing with multiple related classes, a new dataset including images of several hundred mammal classes, is provided, together with preliminary results of its use. The images in this dataset are organized into five levels of variability, and their labels include information on the objects' identity, location and pose. From this dataset, a classification benchmark has been derived, requiring fine distinctions between 72 mammal classes. It is then demonstrated that a recognition method which is highly successful on the Caltech101, attains limited accuracy on the current benchmark (36.5%). Since this method does not utilize the shared structure between classes, the question remains as to whether interclass transfer methods can increase the accuracy to the level of human performance (90%). We suggest that a labeled benchmark of the type provided, containing a large number of related classes is crucial for the development and evaluation of classification methods which make efficient use of interclass transfer.

Insights on the safety of carotenogenic Chlorella vulgaris in rodents

Design of a wear tester for nano-reinforced polymer composites

We consider countable rings with ascending chain condition on right annihilators. We determine the structure of a countable right p-injective Baer ring, a countable semi prime quasi-Baer ring and a countable quasi-Baer biregular ring.

The isolation and preliminary characterisation of a mutation, not linked to the mating type locus, but which apparently alters the mating type directed sequence of events during sexual conjugation is described. Haploids of the alpha mating type carrying this gene will now mate with other alpha haploids, creating diploids homozygous for the alpha mating type locus. This gene can be carried, but not expressed, in a haploids, however in a/alpha diploids homozygous for this gene mating is now possible with both a and alpha haploids giving either a/a/alpha or a/alpha/alpha triploids. Using these strains mating-deficient mutants have been isolated and preliminary results on their characterisation presented.