Material of tesseraspids (Tesseraspidiformes) is reported from the uppermost Severnaya Zemlya Formation

(Lochkovian, Lower Devonian) of the Severnaya Zemlya archipelago, in the Russian Arctic, where it is associated

with other vertebrate remains, including corvaspids, acanthodians, and large but rare specimens of

osteostracans. The tesseraspid material is not abundant, and most often preserved as a “patchwork” of bony

platelets (tesserae), except for a few partly articulated specimens. We redescribe the holotype of Tesseraspis

mosaica Karatajūtė-Talimaa, 1983, whose head carapace is preserved as a flattened tube of adjacent tesserae.

This material is compared to the already published tesseraspid taxa, i.e., T. tessellata Wills, 1935, T. toombsi

Tarlo, 1964, T. mutabilis (Brotzen, 1934), T. oervigi Tarlo, 1964 emend. Dineley and Loeffler, 1976, T. denisoni

Tarlo, 1964, and T. talimaae Tarlo, 1965. All species are based upon rare and incomplete material, as no

head carapaces associated with trunk and tail are known, and so, the intraspecific variability is also unknown.

Distinction between “species” is based on the detail of the superficial sculpture of the tesserae of the head carapaces,

which is unsatisfactory. It is concluded that only four of the nominal species can be retained. A review

of all other known tessellated pteraspidomorphs indicates that our knowledge of tessellated heterostracans is

currently insufficient to support a meaningful classification.

The paper concerns the problem of treatment of the systematic effect as a part of the coverage interval associated with the measurement result. In this case the known systematic effect is not corrected for but instead is treated as an uncertainty component. This effect is characterized by two components: systematic and random. The systematic component is estimated by the bias and the random component is estimated by the uncertainty associated with the bias. Taking into consideration these two components, a random variable can be created with zero expectation and standard deviation calculated by randomizing the systematic effect. The method of randomization of the systematic effect is based on a flatten-Gaussian distribution. The standard uncertainty, being the basic parameter of the systematic effect, may be calculated with a simple mathematical formula. The presented evaluation of uncertainty is more rational than those with the use of other methods. It is useful in practical metrological applications.

The paper presents an evaluation with the Type A and B methods for standard uncertainties of coefficients of a polynomial function of order k determined by n points obtained by measurement of input and output quantities. A method for deriving a posteriori distributions of function coefficients based on the transformation of estimator distributions without assuming any a priori distributions is presented. It was emphasized that since the correct values of the standard uncertainty of type A depend on the √ n-k-3 and not on the p √ n-k-1, therefore, with a small number of measurement points, the use of the classical approach leads to a significant underestimation of uncertainty. The relationships for direct evaluation with the type B method of uncertainties caused by uncorrected systematic additive (offset error) and multiplicative (gain error) effects in the measurements of both input and output quantities are derived. These standard uncertainties are determined on the basis of the manufacturers’ declared values of the maximum permissible errors of the measuring instruments used. A Monte Carlo experiment was carried out to verify the uncertainties of the coefficients and quadratic function, the results of which fully confirmed the results obtained analytically.

Digital twin (DT) is a solution for presenting reality in a virtual world. DTs have been discussed in the literature only recently. The aim of this work is to review and analyse literature connected to DTs. Under a systematic literature review the authors searched databases for the information how DTs can support organization operations and how they can support sustainability of companies. A literature review was performed according to a developed research methodology, which covers research questions and keywords identification, selection criteria and results analysis. Databases, such as Web of Science, Scopus and Science Direct, were searched. The titles, abstracts and keywords were searched for works related to digital twins, sustainable development and manufacturing processes. Moreover, the search was focused on real-time monitoring, data, decision-making etc. The keywords used in the searching process are specified in the methodology. Afterwards, quantitate and qualitative analysis were performed taking into account number of publication, year of publications, type of publication, based on keywords and available information concerning the papers. Deeper analysis was performed on available full texts of the papers. The main goal of this paper was to assess how much the specified problem is discussed in literature in the context of production organizations and real-time and what kind of topics are present in publications to indicate future research needs.

The objective of this article is to carry out a systematic review of the literature on multivariate statistical process control (MSPC) charts used in industrial processes. The systematic review was based on articles published via Web of Science and Scopus in the last 10 years, from 2010 to 2020, with 51 articles on the theme identified. This article sought to identify in which industry the MSPC charts are most applied, the types of multivariate control charts used and probability distributions adopted, as well as pointing out the gaps and future directions of research. The most commonly represented industry was electronics, featuring in approximately 25% of the articles. The MSPC chart most frequently applied in the industrial sector was the traditional T2 of Harold Hotelling (Hotelling, 1947), found in 26.56% of the articles. Almost half of the combinations between the probabilistic distribution and the multivariate control graphs, i.e., 49.4%, considered that the data followed a normal distribution. Gaps and future directions for research on the topic are presented at the end.

Agile Project Management is a topic that has become popular both in business and academia, since the publication of the Agile Manifesto – a historic landmark in this subject. In the next 20 years, there was a relevant scientific production that must be analyzed to provoke reflection about the knowledge built up in this period. In this sense, this study aims to analyze the relevant scientific literature on Agile Project Management through a systematic review and a bibliometric analysis of articles published in scientific journals with Digital Object Identifier, in English, from the Web of Science and Scopus databases, from 2001 to 2021. The research results enable us to gain insights into the characteristics of this knowledge domain, regarding its volume and evolutionary trend, main contributors (i.e. scientific journals, authors, and their affiliations), main studies, methods used, and its central thematic axes.

The technology for gob-side entry retaining in steep coal seams is still in the development stage. The

analysis results of the caving structure of main roof, low influence of gateway’s stability because of long

filling distance and weak dynamic effect of the gateway, and the low stress redistribution environment

indicate that using this technology in steep coal seams has significant advantages. Moreover, to reinforce

the waste rock and the soft floor and to better guard against the impact of the waste rock during natural

filling, a rock blocking device and grouting reinforcement method were invented, and theoretical calculations

result show that the blocking device has high safety factor. In addition, we also developed a set of

hydraulic support devices for use in the strengthening support zone. Furthermore, because the retaining

gateway was a systematic project, the selection of the size and shape of the gateway cross section and its

support method during the initial driving stage is a key step. Thus, first, a section the size of bottom width

and roof height of a new gateway was determined to meet any related requirements. Then, according

to the cross sections of 75 statistical gateways and the support technique, it chosen a trapezoidal cross

section when the dip of the coal seam is 35° < α ≤ 45°, a special and an inclined arch cross section when

45° < α ≤ 55°. Eventually, a support system of bolts and cables combined with steel mesh and steel belts

was provided. The support system used optimized material and improved parameters, can enhanced the

self-bearing ability of the surrounding coal and rock masses.

The author discusses systematization of scientific disciplines. He presents two methods of systematization, namely: classification which uses logical divisions, and typologization which relies on Weberian method of defining ideal types. Faced with certain weaknesses of the classification and typologization, the author proposes still another method of science systematization, which he calls ‘theoretical positioning’. Such systematization is accomplished by defining a selected theory with respect to the research processes employed in it. At the time when interdisciplinary studies are becoming more and more popular, theoretical positioning is a useful method of systematization for research purposes. It arranges scientific disciplines in an order that displays their theoretical affinities. That method of systematization not only organizes the multitude of scientific disciplines but also indicates which areas of cooperation can be most promising. Alongside that study, the author also discusses the possibility of theoretical positioning of sciences by employing conceptual categories used in theory of action which, appropriately conceptualized, could serve as effective interdisciplinary instruments.

This article presents the peculiarities and methodical principles for designing the technologies and forms of organization of the construction liquidation cycle for typical unified series of residential buildings. The systematic approach for developing the necessary settings and indicators of the structure of a complex technological process for disassembling, destructing and demolishing of structural elements and buildings in general is given. The multigraph is created for the closed walk model of correlation of the parameters of the organizational and technological solutions of the construction liquidation cycle.