Three new species of Mesacanthion Filipjev, 1927 (Nematoda: Thoracostomopsidae) from Argentine coasts

Three new species of Mesacanthion Filipjev, 1927 were found along Patagonian coasts (Argentina). Mesacanthion bifidum sp. nov. is characterized by short labial and cephalic setae, onchia of equal size, spicule arcuate, and gubernaculum with caudal apophysis, ending in two teeth. The species is related to M. virile (Ditlevsen, 1930) De Coninck & Schuurmans Stekhoven, 1933. However, the spicules and gubernaculum of both species are different in shape. Mesacanthion longigubernaculum sp. nov. is characterized by its long and slender body, striated cuticle, relatively long cephalic and cervical setae, onchia of different sizes, amphidial fovea lentil-shaped, spicule arcuate, gubernaculum surrounding the spicule, and tail conical-cylindrical with terminal setae. Mesacanthion sanantoniensis sp. nov. is characterized by its long and stout body, striated cuticle, long cephalic setae, onchia of different sizes, amphidial fovea pouch-shaped, spicule arcuate, gubernaculum with dorsal apophysis, and tail conical without terminal setae. Following the key of Jeong et al. (2019), the last two species are related to M. pali Wieser, 1959 and M. longissimesetosum Wieser, 1953, so we provide a key to differentiate the four species.

Together alone: a group-based polarization measurement

The growing polarization of our societies and economies has been extensively studied in various disciplines and is subject to public controversy. Yet, measuring polarization is hampered by the discrepancy between how polarization is conceptualized and measured. For instance, the notion of group, especially groups that are identified based on similarities between individuals, is key to conceptualizing polarization but is usually neglected when measuring polarization. To address the issue, this paper presents a new polarization measurement based on a grouping method called “Equal Size Binary Grouping” (ESBG) for both uni- and multi-dimensional discrete data, which satisfies a range of desired properties. Inspired by techniques of clustering, ESBG divides the population into two groups of equal sizes based on similarities between individuals, while overcoming certain theoretical and practical problems afflicting other grouping methods, such as discontinuity and contradiction of reasoning. Our new polarization measurement and the grouping method are illustrated by applying them to a two-dimensional synthetic data set. By means of a so-called “squeezing-and-moving” framework, we show that our measurement is closely related to bipolarization and could help stimulate further empirical research.

Adjustment of drilling slurry density during transportation by Platform Supply Vessels

Annotation – The issues of maintaining the drilling fluid density during its transportation from shore to the oil drilling platform by the Platform Supply Vessels were considered. The research was carried out on the vessel of 5650 deadweight tons, which made 2 ... 2.5 day voyages from port to drilling platform with possible waiting for direct approach to the platform for 1 ... 1.5 days. The drilling fluid was transported in four tanks of equal-size, arranged in pairs on each side of the vessel. It was found that during this period of time there is a latent stratification of drilling fluid along the depth of cargo tank, causing stratification of its density. The density of the drilling fluid was measured at depths corresponding to 10, 50 and 90 % of the total tank depth. The drilling fluid density stratification is defined as the relative density change in the upper (at 10 % depth) and lower (at 90 % depth) parts of the cargo tank. The hydrometer was used to measure density, allowing measurements in the range of 650 ... 1630 kg/m3 with an accuracy of 1 kg/m3 while controlling the temperature. Density measurements were taken at 6-hour intervals. It has been experimentally proved that during the 48-hour transportation of the drilling fluid with the density of 1295 kg/m3, the density value at the indicated depths is 1163 and 1524 kg/m3 respectively, while the density stratification reaches 31 %. It is offered to prevent the density stratification by creating a forced X-shaped circulation of the drilling fluid between cargo tanks which stand side by side. It is offered to regulate and maintain automatically the drilling fluid density in the range of 2 ... 7 % by using programmable controllers. When the density stratification reaches 7 %, the controller switches on the circulation pumps and circulates the drilling fluid between tanks which stand side by side. This increases the drilling fluid uniformity and helps to reduce the density stratification along the depth of the cargo tank. The process of additional circulation of the drilling fluid is rationally ensured until the density stratification reaches a value of 2 %. Fulfilment of the above-mentioned conditions will ensure that the drilling fluid maintains its operational properties and the energy consumption associated with the additional operation of the circulation pumps is minimised.

Introduction to Set Shaping Theory

In this article, we define the Set Shaping Theory whose goal is the study of the bijection functions that transform a set of strings into a set of equal size made up of strings of greater length. The functions that meet this condition are many but since the goal of this theory is the transmission of data, we have analyzed the function that minimizes the average information content. The results obtained show how this type of function can be useful in data compression.

Optimal Design of Magneto-Force-Thermal Parameters for Electromagnetic Actuators with Halbach Array

A magnetic levitation isolation system applied for the active control of micro-vibration in space requires actuators with high accuracy, linear thrust and low power consumption. The magneto-force-thermal characteristics of traditional electromagnetic actuators are not optimal, while actuators with a Halbach array can converge magnetic induction lines and enhance the unilateral magnetic field. To improve the control effect, an accurate magnetic field analytical model is required. In this paper, a magnetic field analytical model of a non-equal-size Halbach array was established based on the equivalent magnetic charge method and the field strength superposition principle. Comparisons were conducted between numerical simulations and analytical results of the proposed model. The relationship between the magnetic flux density at the air gap and the size parameters of the Halbach array was analyzed by means of a finite element calculation. The mirror image method was adopted to consider the influence of the ferromagnetic boundary on the magnetic flux density. Finally, a parametric model of the non-equal-size Halbach actuator was established, and the multi-objective optimization design was carried out using a genetic algorithm. The actuator with optimized parameters was manufactured and experiments were conducted to verify the proposed analytical model. The difference between the experimental results and the analytical results is only 5%, which verifies the correctness of the magnetic field analytical model of the non-equal-size Halbach actuator.

Connectivity Properties of Generalized K4-Hypercubes

We consider the class of generalized hypercubes constructed recursively from the graph [Formula: see text] by repeatedly taking two copies of such a graph with a perfect matching added in between. We show that all graphs obtained this way have very good connectivity properties. They are all maximally connected, and even when linearly many vertices are deleted, the remaining graph will have a large connected component with only a few vertices in other components. We also show examples that we can delete more vertices in certain graphs in this class to get the second largest component to have certain sizes, including the case when we get two components of equal size. We conjecture that these examples are best possible.

A Set of Batched Basic Linear Algebra Subprograms and LAPACK Routines

This article describes a standard API for a set of Batched Basic Linear Algebra Subprograms (Batched BLAS or BBLAS). The focus is on many independent BLAS operations on small matrices that are grouped together and processed by a single routine, called a Batched BLAS routine. The matrices are grouped together in uniformly sized groups, with just one group if all the matrices are of equal size. The aim is to provide more efficient, but portable, implementations of algorithms on high-performance many-core platforms. These include multicore and many-core CPU processors, GPUs and coprocessors, and other hardware accelerators with floating-point compute facility. As well as the standard types of single and double precision, we also include half and quadruple precision in the standard. In particular, half precision is used in many very large scale applications, such as those associated with machine learning.