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This study examines how internal research and development (R&D), external knowledge acquisition, and R&D contracted with other companies interact in local and foreign-owned enterprises in post-communist economies. A large sample of firm-level data from the Business Environment and Enterprise Performance Survey (BEEPS) across 26 post-communist countries (including European Union (EU) members and non-EU states of Eastern Europe, Caucasian countries, and Central Asian countries) and country-level data from the Global Innovation Index and the International Property Rights Index were used. The findings show that enterprises with majority foreign ownership are relatively more likely to acquire external R&D. We demonstrate that the R&D behavior of enterprises with majority foreign ownership and local firms are interrelated, that is, we find a synergy effect. According to the results, decisions on internal R&D and the purchase of external knowledge for enterprises with majority foreign ownership are similar to those of local firms. However, enterprises with foreign ownership contract R&D with other companies more often if local firms conduct internal R&D. These results indicate the presence of knowledge spillover and cross-learning effects in both types of enterprises in post-communist countries. Finally, we find that the national innovation environment is not significant for the R&D intensity of enterprises with majority foreign ownership, which suggests their high dependence on the parent structures of multinational enterprises.

Purpose: The circumpolar habitat stands as one of the most vulnerable environments for human activity and health. The primary study objective was to compare sleep-related factors, light exposure, social cues, and potential confounding variables among schoolchildren residing in the European Arctic region from two settlements situated below and above the Polar Circle using validated self-reported questionnaires. Materials and Methods: We recruited 94 children aged 13–15 years (40.4% males), matched by sex and age, from public educational institutions in two circumpolar settlements located below (Kem’, Republic of Karelia; 64.6 NL) and above the Polar Circle (Apatity, Murmansk Region; 67.3 NL). Participants completed several surveys, including the Pediatric Daytime Sleepiness Scale, the Insomnia Severity Index, the Adolescent Sleep Hygiene Scale, and the Munich ChronoType Questionnaire, to evaluate sleep parameters and chronotype. The χ2 test was used to test for differences between proportions. Linear regression and multiple regression models with co-factors were applied to assess the relationship between studied indicators. Results: A noteworthy increase in physical activity was observed in children residing in Kem’ compared to those in Apatity. Children from Apatity showed higher alcohol consumption than their counterparts from Kem’. The overall rate of excessive daytime sleepiness in the sample was 17.1%. Moderate insomnia symptoms were reported in 18.4% of adolescents living in Kem’ and in 25% of respondents living in Apatity, respectively. Notably, participants from Kem’ attained higher academic scores and had longer exposure to sunlight on schooldays. On the other hand, children from Apatity tended to have later bedtimes and sleep-onset times on schooldays. According to the Munich ChronoType Questionnaire data, a reliance on alarm clocks on schooldays, and a higher Sleep Stability Factor based on the Adolescent Sleep Hygiene Scale. Discussion: Our study indicating that higher physical activity and longer sunlight exposure among Kem’ children on schooldays are associated with earlier wake-up times during schooldays, earlier bedtime whole week, reduced dependence on alarm clocks, and higher academic achievements. The results of older schoolchildren differ from many works published previously in the USA, Argentina, and Japan, which could be explained by the season when the study was performed. Here, we observed a negative impact on school performance and sleep parameters in children living in high latitudes, namely in circumpolar regions. Conclusions: Our study points out that adolescents living above the Polar Circle tend to have sleep problems, e.g., late sleep-onset times, higher excessive daytime sleepiness, and insomnia-related symptoms, because of experiencing reduced exposure to natural light. Future research encompassing assessments across all four seasons will provide a more comprehensive understanding.

The article describes the organization process for Bachelors of Engineering and Technology training for project and design activities at Tomsk Polytechnic University. There were justified organizational and pedagogical conditions for effective training of Bachelors of Engineering and Technology for future project and design activities.

For a continuous nonlinear control system on a finite time interval with control constraints, where the right-hand side of the dynamics equations is linear in control and linearizable in the vicinity of the zero equilibrium position, we consider the construction of a feedback according to the Kalman algorithm. For this, the solution of an auxiliary optimal control problem with a quadratic functional is used by analogy with the SDRE approach.Since this approach is used in the literature to find suboptimal synthesis in optimal control problems with a quadratic functional with formally linear systems, where all coefficient matrices in differential equations and criteria can contain state variables, then on a finite time interval it becomes necessary to solve a complicated matrix differential Riccati equations, with state-dependent coefficient matrices. This circumstance, due to the nonlinearity of the system, in comparison with the Kalman algorithm for linear-quadratic problems, significantly increases the number of calculations for obtaining the coefficients of the gain matrix in the feedback and for obtaining synthesis with a given accuracy. The proposed synthesis construction algorithm is constructed using the extension principle proposed by V. F. Krotov and developed by V. I. Gurman and allows not only to expand the scope of the SDRE approach to nonlinear control problems with control constraints in the form of closed inequalities, but also to propose a more efficient computational algorithm for finding the matrix of feedback gains in control problems on a finite interval. The article establishes the correctness of the application of the extension principle by introducing analogs of the Lagrange multipliers, depending on the state and time, and also derives a formula for the suboptimal value of the quality criterion. The presented theoretical results are illustrated by calculating suboptimal feedbacks in the problems of managing three-sector economic systems.

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Introduction. Farmers make extensive use of two-wheel tractors equipped with traction and drive interchangeable units. Two-wheel tractors are required to move evenly with minimal slip of the drive wheels on the soil. The tractive force on the drive wheels of the tillage unit is the decisive power factor in this case. An objective traction force value can be measured only by carrying out experimental studies. Materials and Methods. To determine the traction force on the drive wheels of the twowheel tractor, the design of the experimental stand was proposed and substantiated (RF patent for useful model No. 188610 “Movable module of the test stand”), and a methodology for planning and conducting a multifactor experiment to determine the traction force was developed. Results. As a result of the laboratory tests the calculation dependencies of the tractive force on the drive wheels of the Neva MB23-MultiAGRO Pro two-wheel tractor were obtained. Soil conditions, design and technological parameters, operating modes of the two-wheel tractor, and rolling resistance forces were taken into account. Discussion and Conclusion. The use of the developed regression models of the traction force under the condition of ensuring uniform movement with the minimum permissible slipping of the driving wheels of the two-wheel tractor on the soil will allow obtaining the permissible values of the two-tractor motion speed and form the zones of its most effective functioning.

Introduction. Plowing the soil is a major operation in the cultivation of crops. It is one of the most labor-intensive operations in crop production, accounting for about 40 % of all energy costs. Most of these costs fall on consumed power, ensuring the effective functioning of the motor-block unit with a moldboard plow. Therefore, estimation of power consumed by motor-blocks is the urgent task. Materials and Methods. To solve the problem of determining the energy characteristics of the motor-block unit during plowing, a theoretical analysis was carried out, including values of torque, traction force on running wheels, resistance during their rolling and resistance force at the jointers-depleted plow, with the account for the geometry of the plowing unit based on the motor-block. Dependences of power consumption and specific energy consumption were obtained using the method described below. Results. As a result of our analysis of the power balance, we obtained dependences to find power consumption, as well as the specific energy intensity of plowing the soil with a motor-moldboard plow, which allowed for energy assessment of the functioning of the agricultural unit. Discussion and Conclusion. On the basis of these dependences of the required power and specific energy consumption, taking into account experimental data on interaction of the plow with the soil, design parameters and technological modes of operation of the agricultural unit consisting of motor unit Neva MB-2S-7,5 Pro and plow P1-20/3, were obtained to facilitate the choice of optimal modes of their functioning.

Abstract Background Primary gastric squamous cell carcinoma is an extremely rare malignancy with few case reports reported so far in the current medical literature. Its incidence varies between 0.04 and 0.07% of all gastric malignancies with a male predominance in the sixth decade of life. It has been found that this type of malignancy has a more aggressive behavior and associated poorer prognosis, when compared to gastric adenocarcinoma. Thus, the most appropriate management of this kind of neoplasia is still debatable due to the small number of reported cases. Case presentation We report the case of a 66-year-old man who underwent total gastrectomy with D2 lymphadenectomy for an ulcerative lesion in the fundus of the stomach that turned out to be primary gastric squamous cell carcinoma. Conclusions Upon confirmation of this specific malignancy, the affected patients should be enrolled in strict follow-up protocols after curative surgery, since the risk for metastasis is high. Physicians should maintain high clinical suspicion in order to diagnose these tumors at an early stage, along with the need to rule out any other possible primary sites of squamous malignancy.

Abstract Background Primary pancreatic leiomyosarcoma is an extremely rare entity that needs high clinical suspicion in order to diagnose it at an early stage. Clinical characteristics, diagnosis, and management still remain challenging and controversial, especially in advanced stages, when tumor invades adjacent vessels and organs or gives distant metastases. Case presentation Herein, we describe a case of a 57-year-old woman suffering from advanced pancreatic leiomyosarcoma with thrombosis of the superior mesenteric vein, as well as liver lesions which were suspicious for metastasis. Multidisciplinary team decided for upfront chemotherapy to assess tumor response. Follow-up imaging after the completion of chemotherapy led tumor board to decide for subsequent surgical exploration. The patient underwent exploratory laparotomy and irreversible electroporation ablation of the pancreatic tumor. Postoperative course was uneventful, and she was discharged 10 days later with a plan to receive adjuvant therapy. To the best of our knowledge, this is the first case of pancreatic leiomyosarcoma ever reported, treated with this novel technique of irreversible electroporation that could be an alternative and feasible way for the management of these rare malignancies. Conclusions In conclusion, primary pancreatic leiomyosarcoma is a rare and highly malignant tumor associated with poor prognosis. Nowadays, R0 surgical resection remains the cornerstone treatment, combined with adjuvant and/or neoadjuvant chemotherapy prior to resection. In the advanced setting, when major vessel invasion and distant metastases occur, chemotherapy along with irreversible electroporation ablation could be a helpful and possibly effective modality for the management of this highly aggressive tumor.

Uncrewed aerial vehicles (UAVs) are continuously gaining popularity in a wide spectrum of applications, while their positioning and navigation most often relies on Global Navigation Satellite Systems (GNSS). However, numerous conditions and practices require UAV operation in GNSS-denied environments, including confined spaces, urban canyons, vegetated areas and indoor places. For the purposes of this study, an integrated UAV navigation system was designed and implemented which utilizes GNSS, visual, depth and inertial data to provide real-time localization. The implementation is built as a package for the Robotic Operation System (ROS) environment to allow ease of integration in various systems. The system can be autonomously adjusted to the flight environment, providing spatial awareness to the aircraft. This system expands the functionality of UAVs, as it enables navigation even in GNSS-denied environments. This integrated positional system provides the means to support fully autonomous navigation under mixed environments, or malfunctioning conditions. Experiments show the capability of the system to provide adequate results in open, confined and mixed spaces.