289 research outputs found
What are the implications of Curriculum Learning strategy on IRL methods?: Investigating Inverse Reinforcement Learning from Human Behavior
No full textInverse Reinforcement Learning (IRL) is a subfield of Reinforcement Learning (RL) that focuses on recovering the reward function using expert demonstrations. In the field of IRL, Adversarial IRL (AIRL) is a promising algorithm that is postulated to recover non-linear rewards in environments with unknown dynamics. This study investigates the potential benefits of applying the Curriculum Learning (CL) strategy to the AIRL algorithm. For our experiments, we use a randomized partially observable Markov decision process in the form of a grid-world-like environment. Using only expert demonstrations obtained with an RL algorithm under the true reward function, we train AIRL in a variety of configurations and identify an effective curriculum. Our results show, that a well-constructed curriculum can enhance the performance of AIRL twofold in both key aspects: the speed of convergence and the efficiency of using expert demonstrations. We thus conclude that CL can be a useful addition to an AIRL-based solution. Full code is available online in the supplementary material https://github.com/mikhail-vlasenko/curriculum-learning-IRL.CSE3000 Research ProjectComputer Science and Engineerin
Stemonitis amphorocolumella A. Vlasenko, G. Moreno & V. Vlasenko 2023, sp. nov.
No full textStemonitis amphorocolumella A. Vlasenko, G. Moreno & V. Vlasenko sp. nov. Figs. 1, 2. Mycobank: MB 829603 Description and Diagnosis: —Sporocarps in groups, dark brown, cylindrical, with total height of 6 – 9 mm. Hypothallus is dark brown, shiny, continuous under the colony. Sporotheca is long-cylindrical. The stalk is short, 25 – 40% of the total height, hollow, shiny, dark brown, almost black, reddish brown, in transmitted light orange. Peridium is not completely destroyed, remains in the form of a membranous collar at the base of sporotheca. Columella is cylindrical, similar in color to the stalk, with a bulge of amphora-like or bottle-like shape on top ends, up to 60 µm in diameter in the widest part. Capillitium is well developed, filaments extending from the column, are winding, dark brown, shiny and form a large-mesh network of different diameters (25–200 µm), well noticeable thickenings and/or membranous extensions are found in places of branching. The surface net consists of lighter, sometimes almost hyaline, threads, forming small meshes of 5 – 50 µm in diameter, with separate free endings in the form of spinules up to 12 µm in length. Spores are free, brown in mass, grayish brown in transmitted light, globose, with reticulate ornamentation, 9 – 11 µm in diameter, with 11 – 14 small meshes of reticulum on the visible side of the spore. Etymology: —Has a columella with an amphora-like extension. Type: — RUSSIA. Altai Territory, Aleysky district, 5 kilomerts northeast of the village Borovskoye, Lake Bakhmatovskoye, birch forest with Populus tremula, Padus avium, Caragana arborescens, on dead wood of Betula pendula, 52.689067° N, 82.249050° E, 235 m, substrate samples collected 24 August 2018, V.A. Vlasenko (holotype NSK 1026087). Additional specimens examined: — RUSSIA. Altai Territory, Aleysky district, 5 kilomerts northeast of the village Borovskoye, Lake Bakhmatovskoye, dry birch forest, on stump of Betula pendula, 52.687383° N, 82.245250° E, 233 m, substrate samples collected 24 August 2018, V. A . Vlasenko (paratype NSK 1026086, isoparatype AH 49360). Ecology: —Dead wood of deciduous trees. Distribution: —Currently known only from locality of this types: North Asia, southeast of Western Siberia. GenBank accession numbers: —SSU: OP831185. Comments: —The new species belongs to Stemonitis and differs from the Comatricha Preuss and Stemonaria Nann. -Bremek., R. Sharma & Y. Yamam. has in the double net of capillitium, forming a very lax internal net and a delicate complete surface net as well as a hollow, horny or fibrous stalk, consisting of faint closely set, longitudinal fibres. Among representatives of the Stemonitis genus, only four species have bulbous or membranous apex of the columella— Stemonitis capillitionodosa G. Moreno, D.W. Mitch., C. Rojas & S.L. Stephenson (Moreno et al. 2010), Stemonitis flavogenita E. Jahn (Janh 1904), Stemonitis pseudoflavogenita A. Vlasenko & Novozh. (Vlasenko et al. 2020) and Stemonitis sichuanensis B. Zhang & Yu Li (Zhang & Li 2016). Stemonitis amphorocolumella differs from similar species by several morphological features (Tab. 1). In these species, spores have ornamentation, consisting of spines and warts, while Stemonitis amphorocolumella has reticulate ornamented spores. The peridium of Stemonitis amphorocolumella is partially preserved in the form of a filmy collar at the base of sporotheca, whereas the peridium of S. capillitionodosa, S. flavogenita, S. pseudoflavogenita and S. sichuanensis is always fugacious. Stemonitis amphorocolumella differs from S. capillitionodosa by a well-developed small-mesh delicate complete surface net of capillitium, as well as thickenings in the places of branching of capillary filaments, but not membranous extensions. Stemonitis amphorocolumella differs from S. flavogenit a by the structure and form of the end of columella. The columella of Stemonitis flavogenit a ends with a large filmy extension, while the columella of S. amphorocolumella has a thickened non-filmy ending in the shape of an amphora or bottle. Stemonitis amphorocolumella differs from S. sichuanensis by significantly larger spores, up to 11 μm in diameter, and the presence of spinous free endings on filaments of the capillitium. Stemonitis amphorocolumella differs from S. pseudoflavogenita first of all spores with reticulate ornamentation and also structure and form of the end of columella. Columella of Stemonitis pseudoflavogenita always ending in a funnel-shaped expansion at the apex of the sporotheca in Table 2. The ML analysis based on the 18S nrDNA region showed that the new species is closest to Stemonitis fusca. The genetic distance of the “ Stemonitis amphorocolumella ” branch on the SSU tree is 0.166, with 94% bootstrap support (Fig. 3). The genetic distance of the “ Stemonitis fusca ” branch on the SSU tree is 0.276. Comparison of the sequences of Stemonitis amphoracolumella (OP 831185) and S. fusca (KP323386) aligned using the MAFFT for a common fragment of 797 base pairs showed their significant difference, including 183 nucleotide substitutions and 10 deletions and/or insertions). Thus, the conducted comparative morphological and phylogenetic analysis proves the species independence of Stemonitis amphorocolumella.Published as part of Vlasenko, Anastasia V., Moreno, Gabriel H. & Vlasenko, Vyacheslav A., 2023, Stemonitis amphorocolumella (Stemonitidaceae, Myxomycetes), a new species from Western Siberia, pp. 59-67 in Phytotaxa 592 (1) on pages 61-65, DOI: 10.11646/phytotaxa.592.1.5, http://zenodo.org/record/783567
Linguistic strategies for professional politeness among aspiring managers: An analysis of organizational psycholinguistics
No full textIn order to effectively communicate in a professional setting, it is essential for managers to have a mastery of the language specific to their field. One tool that can be used for professional communication is verbal politeness, which involves using appropriate words and phrases to show respect for the listener and soften unfavourable information. These linguistic units promote a culture of professionalism and ethical business relationships and are a key indicator of a manager's speech competence. A psycholinguistic study examined the usage of polite language by aspiring managers. The participants were 218 undergraduate and graduate students enrolled in the Management program across various universities in Ukraine's oblasts. The organizational psycholinguistics research aimed to assess the extent to which aspiring managers incorporate professional language units such as polite words and phrases in their speech. We analyzed the references of 1,308 respondents to determine how politeness language units corresponded to the structural parts of the document. By studying 928 selected language units of politeness, we could assess the level of politeness markers. This indicator reflects future managers' skill level in applying synonymous ranges of politeness. The analysis found that respondents used various linguistic units to soften the impact of unfavourable information when conveying it to others. These units formed synonymous ranges based on context and semantic content. Only half of the students showed a wide range of knowledge and skills in appropriately using polite language. Thus, aspiring managers need to improve their knowledge and practical skills in using a variety of linguistic units of politeness in business documents. Therefore, we recommend implementing programs to improve communication levels for those pursuing higher education in management.
Disclosure Statement
No potential conflict of interest was reported by the authors.
* Corresponding author: Olena Vlasenko,
0000-0002-1011-1965 [email protected]
RISK MANAGEMENT IN INVESTING IN HUMAN CAPITAL
No full textYurii Vlasenko,Oksana Okhrimenko,Leonid Shmorgun ,Yaroslav Oliinyk,Olesia Sam,ko
N-phosphanyl-imidazolin-2-ylidenes: Novel stable carbenes as bidentate ligands for late transition metals
No full textN-phosphorylated, N-heterocyclic carbenes (NHC) based on the imidazoline skeleton have been prepared for the first time. The free carbenes feature good stability and in best cases they can be stored in the solid state for months at ambient temperature without decomposition. The carbenes are capable of acting as ligands towards late transition metal centers such as silver(I). The resulting complexes are stable and can be employed as reagents for the preparation of complexes of other group 11 metals upon transmetallation. The complexes, one carbene ligand and related compounds have all been structurally characterized
Model studies of dense water overflows in the Faroese Channels
No full textThe overflow of dense water from the Nordic Seas through the Faroese Channel system was investigated through combined laboratory experiments and numerical simulations using the Massachusetts Institute of Technology General Circulation Model. In the experimental study, a scaled, topographic representation of the Faroe-Shetland Channel, Wyville-Thomson Basin and Ridge and Faroe Bank Channel seabed bathymetry was constructed and mounted in a rotating tank. A series of parametric experiments was conducted using dye-tracing and drogue-tracking techniques to investigate deep-water overflow pathways and circulation patterns within the modelled region. In addition, the structure of the outflowing dense bottom water was investigated through density profiling along three cross-channel transects located in the Wyville-Thomson Basin and the converging, up-sloping approach to the Faroe Bank Channel. Results from the dye-tracing studies demonstrate a range of parametric conditions under which dense water overflow across the Wyville-Thomson Ridge is shown to occur, as defined by the Burger number, a non-dimensional length ratio and a dimensionless dense water volume flux parameter specified at the Faroe-Shetland Channel inlet boundary. Drogue-tracking measurements reveal the complex nature of flow paths and circulations generated in the modelled topography, particularly the development of a large anti-cyclonic gyre in the Wyville-Thompson Basin and up-sloping approach to the Faroe Bank Channel, which diverts the dense water outflow from the Faroese shelf towards the Wyville-Thomson Ridge, potentially promoting dense water spillage across the ridge itself. The presence of this circulation is also indicated by associated undulations in density isopycnals across the Wyville-Thomson Basin. Numerical simulations of parametric test cases for the main outflow pathways and density structure in a similarly-scaled Faroese Channels model domain indicate excellent qualitative agreement with the experimental observations and measurements. In addition, the comparisons show that strong temporal variability in the predicted outflow pathways and circulations have a strong influence in regulating the Faroe Bank Channel and Wyville-Thomson Ridge overflows, as well as in determining the overall response in the Faroese Channels to changes in the Faroe-Shetland Channel inlet boundary conditions.</p
Amorphous and crystalline aerosol particles interacting with water vapor: conceptual framework and experimental evidence for restructuring, phase transitions and kinetic limitations
No full textMikhailov E, Vlasenko S, Martin ST, Koop T, Poeschl U. Amorphous and crystalline aerosol particles interacting with water vapor: conceptual framework and experimental evidence for restructuring, phase transitions and kinetic limitations. ATMOSPHERIC CHEMISTRY AND PHYSICS. 2009;9(24):9491-9522.Interactions with water are crucial for the properties, transformation and climate effects of atmospheric aerosols. Here we present a conceptual framework for the interaction of amorphous aerosol particles with water vapor, outlining characteristic features and differences in comparison to crystalline particles. We used a hygroscopicity tandem differential mobility analyzer (H-TDMA) to characterize the hydration and dehydration of crystalline ammonium sulfate, amorphous oxalic acid and amorphous levoglucosan particles (diameter ~100 nm, relative humidity 5–95% at 298 K). The experimental data and accompanying Köhler model calculations provide new insights into particle microstructure, surface adsorption, bulk absorption, phase transitions and hygroscopic growth. The results of these and related investigations lead to the following conclusions:
(1) Many organic substances, including carboxylic acids, carbohydrates and proteins, tend to form amorphous rather than crystalline phases upon drying of aqueous solution droplets. Depending on viscosity and microstructure, the amorphous phases can be classified as glasses, rubbers, gels or viscous liquids.
(2) Amorphous organic substances tend to absorb water vapor and undergo gradual deliquescence and hygroscopic growth at lower relative humidity than their crystalline counterparts.
(3) In the course of hydration and dehydration, certain organic substances can form rubber- or gel-like structures (supramolecular networks) and undergo transitions between swollen and collapsed network structures.
(4) Organic gels or (semi-)solid amorphous shells (glassy, rubbery, ultra-viscous) with low molecular diffusivity can kinetically limit the uptake and release of water and may influence the hygroscopic growth and activation of aerosol particles as cloud condensation nuclei (CCN) and ice nuclei (IN). Moreover, (semi-)solid amorphous phases may influence the uptake of gaseous photo-oxidants and the chemical transformation and aging of atmospheric aerosols.
(5) The shape and porosity of amorphous and crystalline particles formed upon dehydration of aqueous solution droplets depend on chemical composition and drying conditions. The apparent volume void fractions of particles with highly porous structures can range up to ~50% or more (xerogels, aerogels).
(6) For efficient description of water uptake and phase transitions of aerosol particles, we propose not to limit the terms deliquescence and efflorescence to equilibrium phase transitions of crystalline substances. Instead we propose generalized definitions according to which amorphous and crystalline components can undergo gradual or prompt, partial or full deliquescence or efflorescence.
We suggest that (semi-)solid amorphous phases may be important not only in the upper atmosphere as suggested in recent studies of glass formation at low temperatures. Depending on relative humidity, (semi-)solid phases and moisture-induced glass transitions may also play a role in gas-particle interactions at ambient temperatures in the lower atmosphere
Vlasenko V. A. Principle approach to managing the enterprise's investment activities in the conditions of safe implementation of real investment projects / International security studios : managerial, economic, technical, legal, environmental, informative and psychological aspects. International collective monograph. Tbilisi, Georgia : Georgian Aviation University, 2023. 1438 p. PP. 1293–1315
No full textThe conducted research is devoted to the problem of safe implementation of
real investment projects based on the application of a principled approach to managing the
enterprise's investment activities. The work substantiates the expediency of implementing a
real investment project of the production direction according to the main phases of the
investment cycle (pre-investment, investment and production). The stages of the investment
project development process at the enterprise are recommended based on their formalization in
the form of a project cycle, which will include the following stages: formulation of the
investment project (identification); development (preparation) of the investment project plan at
the enterprise; expertise (examination) of the investment project at the enterprise;
implementation of the investment project at the enterprise; assessment of the results of the
enterprise's investment project implementation. The author's version of the algorithm for the
process of developing the technical and economic justification of the investment project at the
enterprise is proposed. The stages of investment project development at the enterprise based on
the monitoring mechanism are summarized. It is recommended to supplement the operational
(production) stage of the project cycle at the enterprise with rehabilitation studies for
individual stages. During the research, it was proposed to implement a real investment project
– the launch of a qualitatively new technological line for the production of control and
measuring devices from environmentally friendly glass at the hypothetical enterprise. The
author recommends the components of the process of evaluating a real investment project or
drawing up a capital investment budget at the hypothetical enterprise. As a result of the
performance evaluation of the proposed real investment project for the hypothetical enterprise,
the feasibility of its implementation was proven by calculating the indicators of Net Present
Value (NPV), Profitability Index (PI), Internal Rate of Return on investments (IRR), Project
Payback Period (PP). The economic and operational characteristics of the proposed
development investment project at the hypothetical enterprise are summarized
How Smart City practices create comfortable environments for low mobile population groups
No full textThe article covers the arrangement of comfortable conditions for physically challenged and low mobile residents in urban environments. Currently, these social categories are discriminated in urban societies. Contemporary cities, their infrastructure fail to satisfy their needs. Their ability to move around and fulfill their potential in urban spaces is limited. In the article, the author provides the findings of the sociological survey, conducted in Novokuznetsk, Kemerovo region, in 2015 – 2016. The survey’s mission was to find out whether the principles of reasonable adjustment of an urban environment to the needs of various groups of residents needed to be integrated into the public policy. This problem turns particularly relevant in the context of the development and introduction of the Smart City practices
Linear Regression Model for Substantiation of Sustainable State Policy in a Digital Economy
No full textO. Dorofyeyev, T. Lozinska, Y. Ponochovnyi and T. Vlasenko, "Linear Regression Model for Substantiation of Sustainable State Policy in a Digital Economy," 2020 IEEE 11th International Conference on Dependable Systems, Services and Technologies (DESSERT), Kyiv, Ukraine, 2020, pp. 399-403, doi: 10.1109/DESSERT50317.2020.9125066The article discusses the use of digital mathematical models in justifying public policy for sustainab economic development. The wider expediency uses of statis
analysis methods to substantiate public administration de in the digital economy is explained, The technique of forming and preparation of experimental data for the construction of a mathematical regression model is described. The hypothesis of normal distribution ofthe input data was tested according to the statistical criteria of Kolmogorov-Smirnov and Lilliefors and Shapiro-Wilk. Box-Cox transformation was used to normalize the data, The linear multiple regression coefficients. are determined by the least squares method. The quality of the resulting model was evaluated using the Student's and Fisher's criteria, The results of the forecast of financial stability of agricultural enterprises for 2020-2022 and the factor indicators indicate the negative dynamics of the effective indicator of their financial condition. The proposed model can be used to continuously monitor the financial condition of agricultural enterprises by linking it to the State Statistics Service of Ukraine
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