ИССЛЕДОВАНИЕ ПРЕОБРАЗОВАТЕЛЯ ПОНИЖАЮЩЕГО ТИПА, ИНВАРИАНТНОГО КО ВХОДНЫМ ВОЗМУЩЕНИЯМ

Control system of buck converter with zero static error in a wide range of input disturbance is described. Results of buck converter simulation in MatLab Simulink with a direct link and without it are showed. Frequency range of stable work for invariant control system is defined.В статье представлена реализация системы управления преобразователем понижающего типа для достижения нулевой статической ошибки при широком изменении входных возмущений. Проведено моделирование в средеMATLAB Simulink преобразователя понижающего типа с прямой связью и без неё. Определен диапазон частот входных возмущений, при котором условие инвариантности выполняется. Библ.6, рис.6.У статті запропонована реалізація системи керування перетворювачем понижуючого типу для отримання нульової статичної помилки при широкій змінні вхідних збурень. Проведено моделювання у середовищі MATLAB Simulinkперетворювача понижуючого типу з прямим зв’язком та без нього. Визначений діапазон частот вхідних збурень, при яких умова інваріантності виконується. Бібл.6, рис.6

INFLUENCE OF ICING ON AIRCRAFT PERFORMANCE OF UNMANNED AERIAL VEHICLE М-10-2 "ОКО"

Purpose: Carry out the analysis of lifting surface area of unmanned aerial aircraft. Icing appeared during test flights of unmanned aerial aircraft. Methods: Analysis of flight results in icing conditions using design flight characteristics of unmanned aerial vehicle and data from flight recorder was conducted. The largest ice formations observed on along whole length leading edge of the wing and whole length leading edge of winglets. Results: Under certain meteorological conditions ice deposits forms on parts of small unmanned aerial vehicle similar to how it is formed on a large-sized aircraft was found in practice. Ice formation distorted wing leading edge and front part and bottom and top wing curves. Analogically way tail unit was distorted by ice formations. In addition icing of front surface of telemetry and video antennas, and front part of airspeed sensor tube was found. Formation belongs to pike-shaped type was specified. Discussion: Icing of lifting surface area of aircraft during flight can cause undesirable consequences both in manned and unmanned aviation. Real test flights of unmanned aerial vehicles of SPCUA “Virazh” of National Aviation University in the winter period showed, that ignorance of icing problem could decrease flight safety level up to aviation accident. Fact of icing was discovered after unmanned aerial vehicle landing.</p

Розробка концепції фазового переходу до адитивної економіки

Об’єктом дослідження є системний комплекс теоретичних засад та практичного динамічно побудованого інструментарію і рекомендацій, пов’язаних із забезпеченням фазового переходу до адитивної економіки. Метою дослідження є розробка науково-методичного комплексу та практичного інструментарію щодо проривного переходу України до моделі цифрової економіки на основі обґрунтування впровадження проривних технології (штучного інтелекту, Інтернету речей, нових матеріалів, альтернативної енергетики, сучасних агротехнологій, цифрових бізнес- платформ, 3D-принтингу, "розумних" мереж, хмарних технологій, ефективного транспорту і логістики, ін.)

A fast approximation of the Voronoi diagram for a set of pairwise disjoint arcs

We propose a method for fast approximation of the Voronoi diagram for a set of pairwise disjoint arcs on a plane. The arcs are represented by parameterized curves. A set of input curves is discretized into partition set, for which the Voronoi diagram is constructed. After merging corresponding Voronoi cells and removing redundant edges, the Voronoi graph is approximated by Bezier curves. We also propose the elaboration and optimization of the approximation. The total complexity of the algorithm is ONlogN in the worst-case

Analysis of energy signatures and planning of heating and domestic hot water energy use in buildings in Norway

Widespread introduction of low energy buildings (LEBs), passive houses, and zero emission buildings (ZEBs) are national target in Norway. In order to achieve better energy performance in these types of buildings and successfully integrate them in energy system, reliable planning and prediction techniques for heat energy use are required. However, the issue of energy planning in LEBs currently remains challenging for district heating companies. This article proposed an improved methodology for planning and analysis of domestic hot water and heating energy use in LEBs based on energy signature method. The methodology was tested on a passive school in Oslo, Norway. In order to divide energy signature curve on temperature dependent and independent parts, it was proposed to use piecewise regression. Each of these parts were analyzed separately. The problem of dealing with outliers and selection of the factors that had impact of energy was considered. For temperature dependent part, the different methods of modelling were compared by statistical criteria. The investigation showed that linear multiple regression model resulted in better accuracy in the prediction than SVM, PLS, and LASSO models. In order to explain temperature independent part of energy signature the hourly profiles of energy use were developed.The authors gratefully acknowledge the support from the Research Council of Norway through the research projects: the Research Centre on Zero Emission Neighbourhoods in Smart Cities (FME ZEN) and Energy for domestic hot water in the Norwegian low emission society under VarmtVann2030 within EnergiX program.publishedVersio

Analysis of energy signatures and planning of heating and domestic hot water energy use in buildings in Norway

Widespread introduction of low energy buildings (LEBs), passive houses, and zero emission buildings (ZEBs) are national target in Norway. In order to achieve better energy performance in these types of buildings and successfully integrate them in energy system, reliable planning and prediction techniques for heat energy use are required. However, the issue of energy planning in LEBs currently remains challenging for district heating companies. This article proposed an improved methodology for planning and analysis of domestic hot water and heating energy use in LEBs based on energy signature method. The methodology was tested on a passive school in Oslo, Norway. In order to divide energy signature curve on temperature dependent and independent parts, it was proposed to use piecewise regression. Each of these parts were analyzed separately. The problem of dealing with outliers and selection of the factors that had impact of energy was considered. For temperature dependent part, the different methods of modelling were compared by statistical criteria. The investigation showed that linear multiple regression model resulted in better accuracy in the prediction than SVM, PLS, and LASSO models. In order to explain temperature independent part of energy signature the hourly profiles of energy use were developed

Analysis of energy signatures and planning of heating and domestic hot water energy use in buildings in Norway

Widespread introduction of low energy buildings (LEBs), passive houses, and zero emission buildings (ZEBs) are national target in Norway. In order to achieve better energy performance in these types of buildings and successfully integrate them in energy system, reliable planning and prediction techniques for heat energy use are required. However, the issue of energy planning in LEBs currently remains challenging for district heating companies. This article proposed an improved methodology for planning and analysis of domestic hot water and heating energy use in LEBs based on energy signature method. The methodology was tested on a passive school in Oslo, Norway. In order to divide energy signature curve on temperature dependent and independent parts, it was proposed to use piecewise regression. Each of these parts were analyzed separately. The problem of dealing with outliers and selection of the factors that had impact of energy was considered. For temperature dependent part, the different methods of modelling were compared by statistical criteria. The investigation showed that linear multiple regression model resulted in better accuracy in the prediction than SVM, PLS, and LASSO models. In order to explain temperature independent part of energy signature the hourly profiles of energy use were developed

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research