Precise Numerical Differentiation of Thermodynamic Functions with Multicomplex Variables

The multicomplex finite-step method for numerical differentiation is an extension of the popular Squire–Trapp method, which uses complex arithmetics to compute first-order derivatives with almost machine precision. In contrast to this, the multicomplex method can be applied to higher-order derivatives. Furthermore, it can be applied to functions of more than one variable and obtain mixed derivatives. It is possible to compute various derivatives at the same time. This work demonstrates the numerical differentiation with multicomplex variables for some thermodynamic problems. The method can be easily implemented into existing computer programs, applied to equations of state of arbitrary complexity, and achieves almost machine precision for the derivatives. Alternative methods based on complex integration are discussed, too.

Peripheral and Central Pain Pathways and Pathophysiology

Pain is an unpleasant sensory experience that may be associated with actual or potential tissue damage. Perception of pain includes 3 aspects: sensory-discriminative (intensity and location), cognitive (bodily sensation), and affective-emotional (suffering). Pain is a complex integration of anatomical pathways, including dorsal root ganglion nociceptive neurons, dorsal horn neurons, spinothalamic and spinobulbar pathways, the thalamus, the cortex, and local modulation. Peripheral and central sensitization may occur after tissue injury. This chapter reviews the peripheral and central processing of pain and concludes with a discussion of pain pathophysiology.

Measuring athletic performance in post-metamorphic fire salamanders

Objective Athletic performances are dynamic movements that are physically challenging and often predict individual success in ecological contexts. They stem from a complex integration of multiple phenotypic traits—e.g., morphological, physiological and behavioural—that dictate animal survival and individual fitness. However, directly quantifying athletic performances can be particularly challenging in cryptic, slow-moving species or not very reactive in attitude. Here we present and describe a rapid, simple, and low-cost method to measure athletic performance in post-metamorphic individuals of the fire salamander Salamandra salamandra. While extremely reactive during the larval stage, adult salamanders are, in fact, cryptic and relatively slow-moving. Results Forcing terrestrial juveniles to swim under standard, albeit ecologically plausible, laboratory conditions, and using an automatic point-mass tracking tool, we were able to measure maximal and average performance indicators of post-metamorphic individuals. This method avoids inter-individual variation in motivation, as it forces individuals to perform at their best. Moreover, with this method, measures of athletic performance will be directly comparable between larval and terrestrial stages, allowing to study the contribution of carryover effects to the wide range of processes implicated in the eco-evo-devo of athletic performance in salamanders.

Modeling of Soft Robotic Grippers Integrated with Fluidic Prestressed Composite Actuators

Soft robotic grippers can gently grasp and maneuver objects. However, they are difficult to model and control due to their highly deformable fingers and complex integration with robotic systems. This paper investigates the design requirements as well as the grasping capabilities and performance of a soft gripper system based on fluidic prestressed composite (FPC) fingers. An analytical model is constructed as follows: each finger is modeled using the chained composite model (CCM); strain energy and work done by pressure and loads are computed using polynomials with unknown coefficients; net energy is minimized using the Rayleigh-Ritz method to calculate the deflected equilibrium shapes of the finger as a function of pressure and loads; and coordinate transformation and gripper geometries are combined to analyze the grasping performance. The effects of prestrain, integration angle, and finger overlap on the grasping performance are examined through a parametric study. We also analyze gripping performance for cuboid and spherical objects and show how the grasping force can be controlled by varying fluidic pressure. The quasi-static responses of fabricated actuators are measured under pressures and loads. It is shown that the actuators' modeled responses agree with the experimental results.This work provides a framework for the theoretical analysis of soft robotic grippers and the methods presented can be ex-tended to model grippers with different types of actuation.

Operators on the vanishing moments subspace and Stieltjes classes for M-indeterminate probability distributions

PurposeIn this work the author gathers several methods and techniques to construct systematically Stieltjes classes for densities defined on R+.Design/methodology/approachThe author uses complex integration to obtain integrable functions with vanishing moments sequence, and then the author considers some operators defined on the vanishing moments subspace.FindingsThe author gather several methods and techniques to construct systematically Stieltjes classes for densities defined on R+. The author constructs explicitly Stieltjes classes with center at well-known probability densities. The author gives a lot of examples, including old cases and new ones.Originality/valueThe author computes the Hilbert transform of powers of |ln⁡x| to construct Stieltjes classes by using a recent result connecting the Krein condition and the Hilbert transform.

Legio: fault resiliency for embarrassingly parallel MPI applications

Due to the increasing size of HPC machines, dealing with faults is becoming mandatory due to their high frequency. Natively, MPI cannot handle faults and it stops the execution prematurely when it finds one. With the introduction of ULFM, it is possible to continue the execution, but it requires complex integration with the application. In this paper we propose Legio, a framework that introduces fault resiliency in embarrassingly parallel MPI applications. Legio exposes its features to the application transparently, removing any integration difficulty. After a fault, the execution continues only with the non-failed processes. We also propose a hierarchical alternative, which features lower repair costs on large communicators. We evaluated our solutions on the Marconi100 cluster at CINECA with benchmarks and real-world applications, showing that the overhead introduced by the library is negligible and it does not limit the scalability properties of MPI.

STRIVING FOR TEACHING EXCELLENCE IN REMOTE COURSE DELIVERY: AN INTRANET RESOURCE HUB FOR ENGINEERING FACULTY

Teaching online in higher education is a complex integration of educational technologies, good pedagogical practices, and content knowledge. Concerns and resistance by instructors may be fueled by lack ofunderstanding and resources, to which faculty administration can respond with targeted, ongoing communication and education. A faculty intranet initiative within the Faculty of Engineering at the University of Alberta was created to support instructors amidst their efforts to prepare and deliver online, remote versions of their courses for the Fall 2020 term. The intranet infrastructure was well-suited for the relevant, timely, and tailored digital resources specific to engineering content and circumstances. Beyond the COVID-19 pandemic, it is intended for the intranet to grow into a collaborative virtual space where users can share their knowledge, experience, and insights to build a community of practice.

Integration index for mobility as a service

The integration in transport informatics is facilitated by the rapid development of Information and Communication Technology. One of the realizations of the integration is Mobility as a Service (MaaS), which is proposed as a data-driven, user-centric, personalized mobility service. It integrates various forms of mobility services covering the entire travel chain. Qualitative methods have been applied in existing studies to analyse the integration of MaaS. However, a comprehensive quantitative method is still missing, which could be introduced as a supplementary tool to compare MaaS services. Therefore, we have developed a weighted elaboration method to calculate the complex integration index for MaaS systems. Three aspects are determined as variables, which are the functions of the MaaS application, involved transport modes as well as the tariff structure. Moreover, the organization as the backbone of such integration is considered as the fourth aspect. The integration phases of MaaS are introduced regarding these four aspects, then the calculation method of the complex index is developed by considering the weighted variables. Fourteen MaaS services are evaluated with the method and categorized by organization aspect. We found that public authority is proposed to be the inter-city MaaS operator, and the private company is proposed to be the MaaS operator in intra-city or national level. Our method may support decision-makers to have an abstract overview of MaaS and identify the possible development stage.

Concussion and Balance in Sports

Balance, spatial orientation and stable vision are imperative factors for sports or any other physical activity. It is achieved and maintained by a complex integration set of sensorimotor control systems that include sensory input from vision, proprioception or somatosensory and the vestibular system. A Sport-Related Concussion (SRC) is an individualized injury that presents a range of clinical signs and symptoms (cognitive, physical, emotional, somatic, and sleep-related). For this reason, SPR is a meaningful public health issue that involves a multidisciplinary team to properly manage it. In the sports medicine filed, Sports-Related Concussion assessment and management has become an argumentative issue. Presently, the consensus includes a combination of subjective examination, combined by multifactorial evaluation batteries that allowed to verify several components of brain function. Athletes frequently complain of dizziness and imbalance subsequent a concussion, and these symptoms can expect increased period to recover and return to play. Balance assessment is an important component of the concussion evaluation, as it can contribute with an awareness about the function of the sensorimotor systems.