<abstract xmlns="http://www.w3.org/1999/xhtml">There is a growing need to analyze data sets characterized by several sets of variables observed on the same set of individuals. Such complex data structures are known as multiblock (or multiple-set) data sets. Multi-block data sets are encountered in diverse fields including bioinformatics, chemometrics, food analysis, etc. Generalized Canonical Correlation Analysis (GCCA) is a very powerful method to study this kind of relationships between blocks. It can also be viewed as a method for the integration of information from <italic>K ></italic> 2 distinct sources (Takane and Oshima-Takane 2002). In this paper, GCCA is considered in the context of multivariate functional data. Such data are treated as realizations of multivariate random processes. GCCA is a technique that allows the joint analysis of several sets of data through dimensionality reduction. The central problem of GCCA is to construct a series of components aiming to maximize the association among the multiple variable sets. This method will be presented for multivariate functional data. Finally, a practical example will be discussed.</abstract>

Faculty of Mathematics and Computer Science

Adam Mickiewicz University, Uniwersytetu Poznańskiego 4

The President Stanisław Wojciechowski State University of Applied Sciences in Kalisz

Generalized canonical correlation analysis for functional data

<abstract xmlns="http://www.w3.org/1999/xhtml">Preliminary studies which may be of significance for research against coronaviruses, including SARS-CoV-2, which has caused an epidemic in China, are presented. An analysis was made of publicly available data that contain information about important metabolites neutralizing coronaviruses. Preliminary studies show that especially Ficus, barley, thistle and sundew should be additionally tested with the aim of producing medicines for coronavirus.</abstract>

Department of Mathematical and Statistical Methods

Meta-analysis of flavonoids with antiviral potential against coronavirus

<abstract xmlns="http://www.w3.org/1999/xhtml">For square contingency tables with nominal categories, a local symmetry model which indicates the symmetric structure of probabilities for only one pair of symmetric cells is proposed. For ordinal square tables, the present paper proposes (1) another local symmetry model for cumulative probabilities from the upper-right and lower-left corners of the table, and (2) a measure to represent the degree of departure from the proposed model. The measure has the form of a weighted harmonic mean of the diversity index, which includes the Shannon entropy as a special case. Examples are given in which the proposed method is applied to square table data on decayed teeth in Japanese women patients.</abstract>

Yokohama City University School of Medicine

Department of Information Sciences, Faculty of Science and Technology

Measure of departure from cumulative local symmetry for square contingency tables having ordered categories

<abstract xmlns="http://www.w3.org/1999/xhtml">In this paper, some problems related to determining experimental plans satisfying the criterion of D-optimality are presented. Moreover, the optimality conditions and relations between the parameters of the chemical balance weighing designs are described, and some construction examples are given.</abstract>

D-optimal chemical balance weighing designs with diagonal covariance matrix of experimental errors

<abstract xmlns="http://www.w3.org/1999/xhtml">There are many methods used to determine the reaction to fire of wood and wood-based materials, ranging from full-scale to small-scale testing. One of the small-scale techniques is the use of the Mini Fire Tube (MFT). The aim of this work is to optimize the assessment of fireproofing preparations for wood and wood-based materials using the MFT. In addition, an evaluation was made of the effectiveness of the protection in relation to the maximum temperature of the control sample. An attempt at optimization was made using the example of pine wood and selected flame retardants. Based on the results of control tests, the critical point (the time at which the average sample temperature reached its maximum value) was calculated (Grześkowiak and Moliński 2019). The effectiveness of the protection at the critical point was determined. Efficiencies were calculated for all time parameters to determine the optimal test time. A formula was proposed for the duration of tests for protected samples, taking as a reference the maximum temperature of the control series. The tests showed that it is possible to shorten the time for testing of the effectiveness of flame retardants based on the time taken to obtain maximum temperature for control samples.</abstract>

Methodological improvement of testing of selected parameters for fire resistance of wood and wood-based materials using the MFT

<abstract xmlns="http://www.w3.org/1999/xhtml">High Nature Value farmlands in Europe are of greatest importance in the conservation of biodiversity. Their environmental importance has been recognized for some time, and has been studied mostly in Western Europe. This article describes the results of multivariate statistical analyses performed on data (13 variables) collected from the latest National Agricultural Census and the CORINE database to provide a typology of farmlands with respect to their nature value at municipality level (LAU 2, Local Administrative Units level 2) across Poland. All municipalities were grouped into eight categories (types). Some of the farmland categories were considered to be High Nature Value farmland (HNVf). The following interrelated variables mostly contributed to the identification of HNVf: share of protected areas and forest, grassland, arable land and fallow, farmland cover diversity, and rate of nitrogen fertilization. HNVf was identified in 958 out of 2173 municipalities, covering 44% of the territory of Poland. The identified HNVf also overlaps partially (61%) with LFAs (Less Favored Areas). Farmlands with the highest nature value are located mostly across mountain and hilly areas, close to forests, and protected areas on lowlands and river valleys. The identified HNV farmlands are characterized by low-input farming systems and a large share of semi-natural habitats with a high landscape mosaic.</abstract>

Department of Experimental Design and Bioinformatics, Faculty of Agriculture and Biology

Warsaw University of Life Sciences – SGGW

Department of Entrepreneurship, Faculty of Economics and Management

Identifying High Nature Value farmlands on a national scale based on multivariate typology at municipality (LAU 2) level

<abstract xmlns="http://www.w3.org/1999/xhtml">We show that, in practice, the standard unit root tests, cointegration tests, and similar tests are unreliable. This conclusion is more generally applicable to other related regression-based tests. In particular, these tests attempt to solve a problem by creating another problem.</abstract>

A note on the irrelevance of unit root tests and cointegration tests

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Biometrical Letters

 Biometrical Letters is the official journal of the Polish Biometric Society, founded in 1964, now published with the financial support of the Ministry of Science and Higher Education. The anonymous double-blind peer review by the two independent reviewers is applied to all the papers.  The purposes of Biometrical Letters are:   publishing papers dealing with various aspects of the analysis and interpretation of results from biometrical experiments, using mathematical and statistical methods;  promoting and extending the use of statistical and mathematical methods in the principal disciplines of life sciences by reporting on the development and application of these methods;  presenting statistical and mathematical tools useful in biometry. Methodological developments should be motivated by interesting problems from life sciences, applied or applicable;  publishing review papers and papers presenting practical use of various methods of data analysis and statistical inference.   The core of most Biometrical Letters articles is statistical inference that sets scientific or policy objectives, motivates methodological development and demonstrates the operation of new methods.  The paper should include a description of the biometrical problem and a section detailing the application of the new methodology.  The Journal welcomes the submission of manuscripts from bioscience, mathematical and statistical theory, biology, genetics, medical statistics, agriculture, forestry, ecology, environmental sciences, biometrics and clinical trials. Case studies and articles on the use and development of statistical software are also welcome.  Rejection Rate   20%   Archiving  Sciendo archives the contents of this journal in Portico - digital long-term preservation service of scholarly books, journals and collections.  Plagiarism Policy  The editorial board is participating in a growing community of Similarity Check System's users in order to ensure that the content published is original and trustworthy. Similarity Check is a medium that allows for comprehensive manuscripts screening, aimed to eliminate plagiarism and provide a high standard and quality peer-review process. 