A design strategy to match the band gap of periodic and aperiodic metamaterials

The focus of this paper is on elastic metamaterials characterised by the presence of wide sub-wavelength band gap. In most cases, such mechanical property is strictly connected to the periodic repetition of the unit cell. Nonetheless, the strict periodicity requirement could represent a drawback. In this paper, we present a design strategy for aperiodic elastic metamaterials in order to achieve the same performances as for the periodic counterparts. This is done by exploiting the concept of separation of modes for different building blocks, arranged in aperiodic fashion. A theoretical explanation is provided, as well as numerical simulations; the concept is validated by means of a set of experimental tests on prototypes that are realized via additive manufacturing.

Nutritional physical examination

The historical interest in the use of physical evaluation skills in clinical settings gained new notoriety at the end of the 20th century with evidence that patients in intensive care units experienced increased morbidity and mortality related to poor nutritional status before and/or during their admission. This awareness of the adverse effects of malnutrition led to the need for screening and evaluation tools to identify nutritional risk. no clinical finding of EFN should be considered a diagnosis per se. It is academic, scientific and clinical consensus that its results should be interpreted as suggestive, being crucial to consider the other methods of clinical evaluation of the patient's nutritional status for the correct global nutritional diagnosis. However, the systematic and periodic repetition of the test may help to follow the evolution of the individual's nutritional status, especially in the long term. In summary, although it requires specialized training and continuous practice of the evaluator and/or the team – in addition to requiring complementary nutritional information – the physical nutritional examination can still be considered an effective adjuvant method in the clinical evaluation of the patient’s nutritional status.

Homogenization of Perforated Elastic Structures

The paper is dedicated to the asymptotic behavior of $\varepsilon$ ε -periodically perforated elastic (3-dimensional, plate-like or beam-like) structures as $\varepsilon \to 0$ ε → 0 . In case of plate-like or beam-like structures the asymptotic reduction of dimension from $3D$ 3 D to $2D$ 2 D or $1D$ 1 D respectively takes place. An example of the structure under consideration can be obtained by a periodic repetition of an elementary “flattened” ball or cylinder for plate-like or beam-like structures in such a way that the contact surface between two neighboring balls/cylinders has a non-zero measure. Since the domain occupied by the structure might have a non-Lipschitz boundary, the classical homogenization approach based on the extension cannot be used. Therefore, for obtaining Korn’s inequalities, which are used for the derivation of a priori estimates, we use the approach based on interpolation. In case of plate-like and beam-like structures the proof of Korn’s inequalities is based on the displacement decomposition for a plate or a beam, respectively. In order to pass to the limit as $\varepsilon \to 0$ ε → 0 we use the periodic unfolding method.

General Character of the Opposition

This introductory chapter presents the opposition of rhythm and meter as a contrast of (1) rhythm as variegated pattern and meter as periodic repetition; and (2) rhythmic and metric accent or, more broadly, rhythm as event and meter as a measurement of the duration of that event. These oppositions are sufficiently commonplace that it has not been necessary to invoke the work of specific theorists except to document the most radical interpretation of metrical accent as durationless. In one form or another, these two interpretations can be found in most current writing on rhythm and meter. Although these interpretations need not be seen as incompatible, there has been a tendency in more systematic treatments to posit one or the other as fundamental. Ultimately, it is in the opposition of meter and rhythm that one encounters most poignantly the opposition of law versus freedom, mechanical versus organic, general versus particular, or constant repetition of the same versus spontaneous creation of the ever new.

Repeat pattern segmentation of print fabric based on adaptive template matching

Patterned fabrics are generally constructed from the periodic repetition of a primitive pattern unit. Repeat pattern segmentation of printed fabrics has a very significant impact on the pattern retrieval and pattern defect detection. In this paper, we propose a new approach for repeat pattern segmentation by employing the adaptive template matching method. In contrast to the traditional method for template matching, the proposed algorithm first selects an adaptive size template image in the repeat pattern image based on the size of the original image and its local maximum edge density. Then it uses the sum of absolute differences as the matching features to identify the matched regions in the original image, and the minimum envelope border of the primitive pattern, typically as a parallelogram, can be determined from the results of the four adjacent matched templates. Finally, image traversal base on the obtained parallelogram is implemented over the original image using minimum information loss theory to produce a well-segmented primitive pattern with a complete edge structure. The results from the experiments conducted using an extensive database of real fabric images show that the proposed algorithm has the advantage of rotation invariance and scaling invariance and will not be affected when the background or foreground color is changed.

Investigation of the Method of Dynamic Microwave Power Redistribution in a Resonator-Type Plasmatron

The investigation results of a dynamic microwave power fmicrowave = 2, 45 ± 0,05 GHz redistribution in a 9000 cm³ reaction-discharge chamber of a microwave resonator-type plasmatron are presented. In order to redistribute the microwave power, a rotating metallic four-blade L-form dissector placed above the reaction-discharge chamber was used. The microwave power in the local points at the axis of the chamber with plasma and without it was measured applying the "active probe" method. During the experiments the chamber contained silicon plates. Periodical interchange of maximum and minimum microwave power values along the chamber axis was established experimentally. Note, when the dissector was rotating, the range of maximum and minimum "active probe" values dispersion decreased. It has been established that during the dissector rotation the microwave power in the local discharge areas changes with periodic repetition every quarter of revolution.

Revisiting Chameleon Sequences in the Protein Data Bank

The steady growth of the Protein Data Bank (PDB) suggests the periodic repetition of searches for sequences that form different secondary structures in different protein structures; these are called chameleon sequences. This paper presents a fast (nlog(n)) algorithm for such searches and presents the results on all protein structures in the PDB. The longest such sequence found consists of 20 residues.

A four-sector polarization converter integrated in a calcite crystal

A new approach to the implementation of sectorial plates for beam polarization conversion is proposed. Using a newly developed etching technology, a four-sector polarization converter integrated into a calcite crystal is implemented. A four-sector polarization converter, which provides a pairwise orthogonal polarization state of the sectors, is fabricated and experimentally characterized. A comparison is made of inter-sector joints of the integrated converter with those of a converter composed of individual wave-plate fragments. Analysis of the spectral properties of such a converter is carried out, wavelengths at which the necessary polarization conversion takes place are determined. The quasi-periodic repetition of phase matching conditions is experimentally shown to slow down with increasing wavelength.

An Adaptive Approach Based on Resource-Awareness Towards Power-Efficient Real-Time Periodic Task Modeling on Embedded IoT Devices

Embedded devices are gaining popularity day by day due to the expanded use of Internet of Things applications. However, these embedded devices have limited capabilities concerning power and memory. Thus, the applications need to be tailored in such a way to perform the specified tasks within the constrained resources with the same accuracy. In Real-Time task scheduling, one of the challenging factors is the intelligent modelling of input tasks in such a way that it produces not only logically correct output within the deadline but also consumes minimum CPU power. Algorithms like Rate Monotonic and Earliest Deadline First compute hyper-period of input tasks for periodic repetition of the same set of tasks on CPU. However, at times when the tasks are not adequately modelled, they lead to an enormously high value of hyper-period which result in more CPU cycles and power consumption. Many state-of-the-art solutions are presented in this regard, but the main problem is that they limit tasks from having all possible period values; however, with the vision of Industry 4.0, where most of the tasks will be doing some critical manufacturing activities, it is highly discouraged to prevent them of a certain period. In this paper, we present a resource-aware approach to minimise the hyper-period of input tasks based on device profiles and allows tasks of every possible period value to admit. The proposed work is compared with similar existing techniques, and results indicate significant improvements regarding power consumptions.

ICMP-based Third-Party Estimation of Cloud Availability

Cloud availability is an important parameter present in a typical Service Level Agreement (SLA). In order to check compliance with SLA commitments, a third party availability measurement is strongly needed. An availability estimation methods is evaluated here, based on the periodic repetition of sequence of probing packets in ICMP. Majority Voting, which declares a cloud to be available only if a majority of probing packets gets an echo from the cloud, appears to provide an accurate estimation even when the packet loss probability is rather high.