Добірка наукової літератури з теми "Correlation-extreme systems"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Correlation-extreme systems".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Статті в журналах з теми "Correlation-extreme systems"
1
Coletti, G., L. C. van der Gaag, D. Petturiti, and B. Vantaggi. "Detecting correlation between extreme probability events." International Journal of General Systems 49, no. 1 (November 21, 2019): 64–87. http://dx.doi.org/10.1080/03081079.2019.1692005.
Повний текст джерела
2
Calderón-Vega, Felícitas, Adrián-David García-Soto, and César Mösso. "Correlation of Concurrent Extreme Metocean Hazards Considering Seasonality." Applied Sciences 10, no. 14 (July 13, 2020): 4794. http://dx.doi.org/10.3390/app10144794.
Повний текст джерелаАнотація:
Simultaneous occurrence of metocean variables can present a multihazard to maritime systems. However, simplified design approaches to assess simultaneous significant wave heights and wind velocities are lacking, especially if seasonality is considered. This is addressed in this study by using extreme significant wave heights and companion wind velocities recorded in the Gulf of Mexico. Time-dependent, generalized extreme value (GEV) models and classical regression are the basis to propose a simplified approach to estimate correlated extreme significant wave heights and wind velocities associated with given return periods, accounting for seasonality and including measures of uncertainty. It is found that the proposed approach is a new but simple method to adequately characterize the concurrent extreme metocean variables and their uncertainty. It is concluded that the method is an effective probabilistic design tool to determine simultaneous extreme significant wave heights and companion wind velocities for desired return periods and seasonality.
3
Kharchenko, Volodymyr, and Maryna Mukhina. "CORRELATION-EXTREME VISUAL NAVIGATION OF UNMANNED AIRCRAFT SYSTEMS BASED ON SPEED-UP ROBUST FEATURES." Aviation 18, no. 2 (July 2, 2014): 80–85. http://dx.doi.org/10.3846/16487788.2014.926645.
Повний текст джерелаАнотація:
The peculiarities of correlation-extreme visual navigation are considered. Descriptors with 64 elements of feature points of surface images are selected on the basis of the speed-up robust feature method. An analysis of possible criteria correlation functions is carried out to find the best match between the template descriptors and current images. The use of normalized correlation function is proposed based on the matrix multiplication properties of descriptors. It allows minimizing the number of false matches in comparison with the Euclidean distance in the descriptor space. The proposed matching strategy sufficiently decreases the computation time.
4
Tantsiura, Alexander. "Evaluation of the Potential Accuracy of Correlation Extreme Navigation Systems of Low-Altitude Mobile Robots." International Journal of Advanced Trends in Computer Science and Engineering 8, no. 5 (October 15, 2019): 2161–66. http://dx.doi.org/10.30534/ijatcse/2019/47852019.
Повний текст джерела
5
Kozhushko, Yaroslav. "Determination of Accuracy of Low-Altitude Navigation of Dynamic Objects Equipped with Correlation-Extreme Systems." International Journal of Advanced Trends in Computer Science and Engineering 9, no. 3 (June 25, 2020): 2981–86. http://dx.doi.org/10.30534/ijatcse/2020/75932020.
Повний текст джерела
6
Hamada, Atsushi, Yuki Murayama, and Yukari N. Takayabu. "Regional Characteristics of Extreme Rainfall Extracted from TRMM PR Measurements." Journal of Climate 27, no. 21 (October 24, 2014): 8151–69. http://dx.doi.org/10.1175/jcli-d-14-00107.1.
Повний текст джерелаАнотація:
Abstract Characteristics and global distribution of regional extreme rainfall are presented using 12 yr of the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) measurements. By considering each rainfall event as a set of contiguous PR rainy pixels, characteristic values for each event are obtained. Regional extreme rainfall events are defined as those in which maximum near-surface rainfall rates are higher than the corresponding 99.9th percentile on a 2.5° × 2.5° horizontal-resolution grid. The geographical distribution of extreme rainfall rates shows clear regional differences. The size and volumetric rainfall of extreme events also show clear regional differences. Extreme rainfall rates show good correlations with the corresponding rain-top heights and event sizes over oceans but marginal or no correlation over land. The time of maximum occurrence of extreme rainfall events tends to be during 0000–1200 LT over oceans, whereas it has a distinct afternoon peak over land. There are also clear seasonal differences in which the occurrence over land is largely coincident with insolation. Regional extreme rainfall is classified by extreme rainfall rate (intensity) and the corresponding event size (extensity). Regions of “intense and extensive” extreme rainfall are found mainly over oceans near coastal areas and are likely associated with tropical cyclones and convective systems associated with the establishment of monsoons. Regions of “intense but less extensive” extreme rainfall are distributed widely over land and maritime continents, probably related to afternoon showers and mesoscale convective systems. Regions of “extensive but less intense” extreme rainfall are found almost exclusively over oceans, likely associated with well-organized mesoscale convective systems and extratropical cyclones.
7
Salgueiro, João Hipólito Paiva de Britto, Suzana Maria Gico Lima Montenegro, Eber José de Andrade Pinto, Bernardo Barbosa da Silva, Werônica Meira de Souza, and Leidjane Maria Maciel de Oliveira. "Influence of oceanic-atmospheric interactions on extreme events of daily rainfall in the Sub-basin 39 located in Northeastern Brazil." RBRH 21, no. 4 (October 24, 2016): 685–93. http://dx.doi.org/10.1590/2318-0331.011616023.
Повний текст джерелаАнотація:
ABSTRACT Changes in extreme precipitation have been observed in regions where frequent rainfalls occur over short periods of time followed by prolonged droughts, creating, as a result, new watershed scenarios. Recent studies have attributed such occurrences to possible climate changes. This paper analyzes the correlation between extreme events recorded in the Sub-basin 39, located in Northeastern Brazil, and the anomalies caused by sea surface temperature - SST and the atmospheric systems operating in the region. Pearson correlation coefficients have been used combined with the variables analyzed. For such, trends in precipitation have been obtained by using the method of least squares together with linear regression and the Student's t test. The results obtained have demonstrated that due to the geographical position of the region investigated, both maximum extreme events (areas with positive trends) and minimum extreme events (areas with negative trends) are more dependent on the Dipole Atlantic than on the effects of El Niño Southern Oscillation - ENOS.
8
Liashko, Olha. "The Criterion and Evaluation of Effectiveness of Image Comparison in Correlation-Extreme Navigation Systems of Mobile Robots." International Journal of Emerging Trends in Engineering Research 8, no. 6 (June 25, 2020): 2841–47. http://dx.doi.org/10.30534/ijeter/2020/97862020.
Повний текст джерела
9
Dawley, Shawn, Yong Zhang, Xiaoting Liu, Peng Jiang, Geoffrey Tick, HongGuang Sun, Chunmiao Zheng, and Li Chen. "Statistical Analysis of Extreme Events in Precipitation, Stream Discharge, and Groundwater Head Fluctuation: Distribution, Memory, and Correlation." Water 11, no. 4 (April 5, 2019): 707. http://dx.doi.org/10.3390/w11040707.
Повний текст джерелаАнотація:
Hydrological extremes in the water cycle can significantly affect surface water engineering design, and represents the high-impact response of surface water and groundwater systems to climate change. Statistical analysis of these extreme events provides a convenient way to interpret the nature of, and interaction between, components of the water cycle. This study applies three probability density functions (PDFs), Gumbel, stable, and stretched Gaussian distributions, to capture the distribution of extremes and the full-time series of storm properties (storm duration, intensity, total precipitation, and inter-storm period), stream discharge, lake stage, and groundwater head values observed in the Lake Tuscaloosa watershed, Alabama, USA. To quantify the potentially non-stationary statistics of hydrological extremes, the time-scale local Hurst exponent (TSLHE) was also calculated for the time series data recording both the surface and subsurface hydrological processes. First, results showed that storm duration was most closely related to groundwater recharge compared to the other storm properties, while intensity also had a close relationship with recharge. These relationships were likely due to the effects of oversaturation and overland flow in extreme total precipitation storms. Second, the surface water and groundwater series were persistent according to the TSLHE values, because they were relatively slow evolving systems, while storm properties were anti-persistent since they were rapidly evolving in time. Third, the stretched Gaussian distribution was the most effective PDF to capture the distribution of surface and subsurface hydrological extremes, since this distribution can capture the broad transition from a Gaussian distribution to a power-law one.
10
Vieira, Fabrício, Maurício Ribeiro, Antonio Francisco, and Giane Gonçalves Lenzi. "Influence of Extreme Events in Electric Energy Consumption and Gross Domestic Product." Sustainability 11, no. 3 (January 28, 2019): 672. http://dx.doi.org/10.3390/su11030672.
Повний текст джерелаАнотація:
The objective of this paper was to identify how extreme events can indicate periods of economic instability in variables from the economic and environmental context (per capita Gross Domestic Product (GDP), per capita electric energy consumption, and per capita carbon dioxide (CO2) emission). The research is limited to the population of the country (Brazil) and five cities of Paraná (Curitiba, Londrina, Maringá, Ponta Grossa, and Cascavel). Therefore, the major research interest was focused on finding information related to extreme events and other techniques that are used for interpretation of complex systems currently. The development was based on data collection. The results indicated that extreme events have influence in periods of economic instability. They also evidenced that there is greater correlation in GDP data/electric energy consumption than in GDP data/CO2 emissions or electric energy consumption/CO2 emissions.
Дисертації з теми "Correlation-extreme systems"
1
Sotnikov, A., Yu Koltun, and N. Yeromina. "The formation of reference images based on the brightness characteristics of reference area." Thesis, Технологічний центр, 2020. https://openarchive.nure.ua/handle/document/16394.
Повний текст джерела
2
Dahlstedt, Kajsa Mime Linnea. "Properties of macroscopic fluctuations in physical systems : correlation structure, scaling and extreme value statistics." Thesis, Imperial College London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498007.
Повний текст джерела
3
Литвинець, Олександра Леонідівна. "Алгоритм кореляційно-екстремального стеження за безпілотним літальним апаратом за даними відеоспостереження". Master's thesis, КПІ ім. Ігоря Сікорського, 2020. https://ela.kpi.ua/handle/123456789/41306.
Повний текст джерелаАнотація:
Магістерська робота на тему «Алгоритм кореляційно-екстремального стеження за безпілотним літальним апаратом за даними відеоспостереження» складається з 8 розділів, 83 сторінки, 1 додатку, 60 ілюстрацій по тексту роботи та 20 таблиць. Використано 11 посилань.
На сьогоднішній день прогресивний розвиток пілотної та безпілотної авіації, систем управлінням повітряними та наземними об'єктами пересування, створює необхідність у розробці технологій, що виявляють та супроводжують об'єкти у просторі. Найбільш широке застосування вони віднайшли у задачах навігації, космічного моніторингу Землі, забезпечення безпеки, бортових систем, що встановлюються у літаках, гелікоптерах та автомобілях, та охоронних послуг.
Необхідність у використання методів виявлення та супроводження зростає у зв’язку з розширенням області застосування БПЛА, що можуть бути об’єктами-правопорушниками. Підвищення ефективності оптико-електронних систем необхідно для задач охорони та захисту закритих територій від несакціонованого проникнення, забезпечення їх приватності від безпілотних літаючих апаратів.
Сучасні БПЛА можуть мати не тільки маленькі розміри та високу автономність, але і надзвичайно високу маневреність. Як наслідок, постійно підвищується вимоги комплексів, що обробляють поставлені цілі, а тому це приводить до поліпшення вже існуючих технологій та розробки нових методів і алгоритмів для вирішення поставлених задач.
В роботі розглянута розробка та аналіз алгоритм кореляційно-екстремального стеження за безпілотним літальним апаратом за даними відеоспостережень.
Метою дослідження є покращення характеристик стеження за малорозмірними БПЛА системою відеоспостереження, шляхом розробки кореляційно-екстремального алгоритма стеження.
Об’єкт дослідження – процес стеження за малорозмірними БПЛА системою відеоспостереження.
Предмет дослідження – методи стеження за малорозмірними БПЛА за даними відеоспостережень.
Для досягнення поставленої мети необхідно вирішити такі завдання:
- провести аналіз сучасних телевізійних систем відеоспостереження;
- виконати аналіз кореляційно-екстремальних методів зіставлення зображень;
- розглянути можливості застосування метода калманівської фільтрації для стеження за точковими цілями;
- розробити алгоритм кореляційно-екстремального стеження за малорозмірним БПЛА на основі методу калманівської фільтрації;
- оцінити ефективність розробленого алгоритму за допомогою статичного моделювання на ЕОМ;.
- розглянути можливості практичної реалізації розробленого алгоритму.The topic of master thesis is “Algorithms for correlation-extreme tracking of an unmanned aerial vehicle based on video data”. The research work consists of 8 paragraphs, 83 pages, 60 illustrations and 20 tables. In total, 11 references links were used. Nowadays, the progressive development of pilot and unmanned aerial vehicles, air and ground control systems, creates a need to develop technologies that detect and watch/tracks objects. They are most widely used in navigation, space monitoring, security, on-board systems installed in aircraft, helicopters and cars, and security services. The need for detection and tracking methods is growing due to the expansion of the scope of UAVs using and as a result the exceeding of the limits which are allowed. Improving the efficiency of optoelectronic systems is necessary for the tasks of protection and defense of closed areas from unauthorized intrusion, ensuring their privacy from unmanned aerial vehicles. Modern UAVs can have not only small size and high autonomy but also extremely high maneuverability. As a result, the requirements of systems that process the set goals are constantly increasing, and therefore it leads to the improvement of existing technologies and the development of new methods and algorithms for solving these aims. The research work considers the development and analysis of an algorithm for correlation-extreme tracking of an unmanned aerial vehicle based on video data. The aim of the work is to improve the characteristics of tracking UAVs by video system surveillance, by developing a correlation-extreme tracking algorithm. The research object is the process of monitoring UAVs by the video surveillance system. The research subject is the methods of tracking UAVs by the video surveillance system. To achieve these goals have been resolved following tasks: - to analyze modern television video surveillance systems; - to analyze correlation-extreme methods of image comparison; - to consider the possibility of applying the method of Kalman filtering for UAVs tracking; - to develop an algorithm for correlation-extreme tracking of an unmanned aerial vehicle based on video data; - to evaluate the effectiveness of the developed algorithm using static simulation on a computer; - to consider the possibilities of practical implementation of the developed algorithm.
Магистерская работа на тему «Алгоритм корреляционно-экстремального слежения за беспилотным летательным аппаратом по данным видеонаблюдения» состоит из 8 разделов, 83 страницы, 1 приложения, 60 иллюстраций по тексту работы и 20 таблиц. Использовано 11 ссылок. На сегодняшний день прогрессивное развитие пилотной и беспилотной авиации, систем управлением воздушными и наземными объектами передвижения, создает необходимость в разработке технологий, обнаружения и сопровождающие объектов в пространстве. Наиболее широкое применение они нашли в задачах навигации, космического мониторинга Земли, обеспечения безопасности, охранных услуг, бортовых систем, устанавливаемых в самолетах, вертолетах и автомобилях. Необходимость в использовании методов обнаружения и сопровождения растет в связи с расширением области применения БПЛА, которые могут быть объектами-правонарушителями. Повышение эффективности оптико-электронных систем необходимо для задач охраны и защиты закрытых территорий от несакционованого проникновения, обеспечение их конфиденциальности от беспилотных летательных аппаратов. Современные БПЛА могут иметь не только маленькие размеры и высокую автономность, но и чрезвычайно высокую маневренность. Как следствие, постоянно повышается требования к системам, обрабатывающих поставленные цели, а потому это приводит к улучшению уже существующих технологий и разработки новых методов и алгоритмов для решения поставленных задач. В работе рассмотрена разработка и анализ алгоритма корреляционно-экстремального слежения за беспилотным летательным аппаратом по данным видеонаблюдения. Целью исследования является улучшение характеристик слежения за малоразмерными БПЛА системой видеонаблюдения, путем разработки корреляционно-экстремального алгоритма слежения. Объект исследования - процесс слежения за малоразмерными БПЛА системой видеонаблюдения. Предмет исследования - методы слежения за малоразмерными БПЛА по данным видеонаблюдения. Для достижения поставленной цели необходимо решить следующие задачи: - провести анализ современных телевизионных систем видеонаблюдения; - выполнить анализ корреляционно-экстремальных методов сопоставления изображений; - рассмотреть возможности применения метода калмановской фильтрации для слежения за точечными целями; - разработать алгоритм корреляционно-экстремального слежения за малоразмерным БПЛА на основе метода калмановской фильтрации; - оценить эффективность разработанного алгоритма с помощью статического моделирования на ЭВМ ;. - рассмотреть возможности практической реализации разработанного алгоритма.
4
A, Kuzmenko. "CORRELATION-EXTREME NAVIGATION SYSTEM BASED ON MORPHOLOGICAL ANALYSIS." Thesis, ПОЛІТ.Сучасні проблеми науки.Гуманітарні науки:тези доповідей XVII Міжнародної науково-практичної конференції молодих учених і студентів:[y 2-x т.].Т.2(м.Київ,4-7 квітня 2017 р.)/[ред.кол.:В.М.Ісаєнко та ін.]; Національний авіаційний університет.-К.:НАУ,2017.-374 с, 2017. http://er.nau.edu.ua/handle/NAU/27745.
Повний текст джерелаАнотація:
Therefore, advantage of morphological method is associated with the possibility of improving the integration of image registration conditions. Introduced by morphological analysis the notion of «form» significantly enriches the radiometric properties of reference image, making possible to build a more robust detection algorithms.
5
Yu, Tkachenko O. "CORRELATION-EXTREME SYSTEM OF INERTIAL DEAD RECKONING CORRECTED BY LINEAR LANDMARK." Thesis, ПОЛІТ.Сучасні проблеми науки.Гуманітарні науки:тези доповідей XVII Міжнародної науково-практичної конференції молодих учених і студентів:[y 2-x т.].Т.2(м.Київ,4-7 квітня 2017 р.)/[ред.кол.:В.М.Ісаєнко та ін.]; Національний авіаційний університет.-К.:НАУ,2017.-374 с, 2017. http://er.nau.edu.ua/handle/NAU/27740.
Повний текст джерелаАнотація:
The purpose of the work is to solve the problem of external orientation by searching linear landmarks on images of geophysical field, received from UAV. Currently existing navigation systems of unmanned aerial vehicles (UAVs) are characterized by a high dependency on the information received from the satellite navigation system (SNS), such as GPS/GLONASS.
6
A, Kuzmenko. "Correlation-extreme navigation system based on morphological analysis." Thesis, 2017. http://er.nau.edu.ua/handle/NAU/27843.
Повний текст джерелаАнотація:
Relevance of research topic is caused by the fact that the comparison of images based only on the brightness characteristics is not sufficient sometimes, but morphological comparison considers also geometric characteristics.
Purpose of research is to disclose the principle of work and efficiency of Correlation-Extreme Navigation System (CENS) based on morphological analysis. Unmanned Aerial Vehicles (UAVs) always contains Global Positioning System (GPS) and Inertial Measurement Unit (IMU). It usually has the ability to perform automatic navigation along planned waypoints. Nevertheless, if the GPS signal becomes unavailable, the state estimation solution provided by data from
IMU alone drifts in time and will be unusable. Correlation-extreme navigation is one of alternative solution in such case and may be additional source of data fusion in the integrated navigation complex.
7
Yu, Tkachenko O. "Correlation-extreme system of inertial dead reckoning corrected by linear landmark." Thesis, 2017. http://er.nau.edu.ua/handle/NAU/27841.
Повний текст джерелаАнотація:
The purpose of the work is to solve the problem of external orientation by
searching linear landmarks on images of geophysical field, received from UAV.
Currently existing navigation systems of unmanned aerial vehicles (UAVs) are characterized by a high dependency on the information received from the satellite navigation system (SNS), such as GPS/GLONASS.
Частини книг з теми "Correlation-extreme systems"
1
Frolov, Sergey G., and Anatoly M. Korikov. "Correlation-Extreme Systems of Defect Search in Pipeline Networks." In Advances in Intelligent Systems and Computing, 385–94. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-51971-1_32.
Повний текст джерела
2
Su, Lijuan, Min Yao, Nenggan Zheng, and Zhaohui Wu. "Correlation Between Extreme Learning Machine and Entorhinal Hippocampal System." In Proceedings in Adaptation, Learning and Optimization, 307–15. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-28373-9_26.
Повний текст джерела
3
Grassi, A., G. M. Lombardo, and G. Forte. "Simple Approaches to Calculate Correlation Energy in Polyatomic Molecular Systems." In Correlations in Condensed Matter under Extreme Conditions, 279–87. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-53664-4_20.
Повний текст джерела
4
Maun, M. Anwar. "Burial by sand." In The Biology of Coastal Sand Dunes. Oxford University Press, 2009. http://dx.doi.org/10.1093/oso/9780198570356.003.0011.
Повний текст джерелаАнотація:
In coastal dune systems, plant communities are fundamentally the product of interaction between disturbance of the substrate, impact of high wind velocities, salt spray episodes, sand accretion levels and other factors of the environmental complex. Burial by sand is probably the most important physical stress that alters species diversity by eliminating disturbance-prone species (Maun 1998). There is a close correlation between sand movement and species composition, coverage and density (Moreno-Casasola 1986; Perumal 1994; Martínez et al. 2001). Sand accretion kills intolerant species, reduces the relative abundance of less tolerant species and increases the abundance of tolerant species. It filters out species as the level of burial starts to exceed their levels of tolerance. For example, lichens and mosses are the first to be eliminated, then the annuals and biennials and finally the herbaceous and woody perennials. Again within each life form and genus there are significant differences in survivability. Burial imposes a strong stress on production by altering normal growth conditions and exposing plants to extreme physiological limits of tolerance. Do plant communities occurring in different locations within a dune system correspond to the amount of sand deposition? Several studies (Birse et al. 1957; Moreno- Casasola 1986; Perumal 1994) show that the species composition and their distribution are strongly related to the long-term average sand deposition. The evolution of a plant community in coastal foredunes requires frequent and persistent predictable burial events specific to a particular coast. In a large majority of sea coasts burial occurrences are of relatively low magnitude and species occupying the coasts are well adapted to withstand the stress imposed by burial. This recurring event within the generation times of plant species allows them to acquire genes of resistance over time and evolution of adaptations to live in this habitat. A prerequisite to survive in this habitat happens to be the ability to withstand partial inundation by sand. To survive the dynamic substrate movement a plant species must be a perennial, be able to withstand burial, endure xerophytic environment, spread radially and vertically, and adapt to exposure on deflation and coverage on burial (Cowles 1899).
Тези доповідей конференцій з теми "Correlation-extreme systems"
1
Wang, Yong, Zhong Xu, Kai Zhou, Junxiang Liu, Qianwen Guo, and Weinan Fan. "On the Correlation Model between Extreme Disaster Weather and Distribution Transformer Fault Types." In 2021 IEEE 10th Data Driven Control and Learning Systems Conference (DDCLS). IEEE, 2021. http://dx.doi.org/10.1109/ddcls52934.2021.9455668.
Повний текст джерела
2
Kropotov, Y. A., and A. A. Belov. "Method of correlation-extreme parameter estimation of acoustic echoes in telecommunication audio exchange systems." In 2015 International Siberian Conference on Control and Communications (SIBCON). IEEE, 2015. http://dx.doi.org/10.1109/sibcon.2015.7147108.
Повний текст джерела
3
Wang, Yao, Kerui Ma, Xuxia Li, Yan Liang, Yingying Hu, Jia Li, and Hongli Liu. "Multi-type Load Forecasting of IES Based on Load Correlation and Stacked Auto-Encode Extreme Learning Machine." In 2020 10th International Conference on Power and Energy Systems (ICPES). IEEE, 2020. http://dx.doi.org/10.1109/icpes51309.2020.9349738.
Повний текст джерела
4
Drago, Michele, Matteo Mattioli, and Federico Quondamatteo. "Metocean Design Criteria for Deep Water Offshore Systems." In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-41108.
Повний текст джерелаАнотація:
In the last decades the off-shore hydrocarbon extraction industry has extended its field of activities in very deep waters up to more than 2000 m. Extraction and production systems can vary between complete subsea development with export pipelines to on-shore treatment plants and surface development by means of surface units (SSFU) connected to subsea wells by risers and anchored by mooring systems which extend through the whole water column. For exclusively subsea developments, including sealines, the metocean design data and criteria to be developed and the applicable methodologies to derive them are well established. Univariate theory is usually applied in order to quantify the risk of failure due to (extreme) sea conditions. The surface developments and the connections through the water column (e.g. risers, moorings) are newly challenging aspects. They could suffer from severe damages due to the occurrence of critical combinations of different variables during a single sea storm:: thus, it may be important to consider the joint occurrence of different forcing conditions (i.e. multivariate analysis). The present manuscript provides a simplified methodology in order to carry out a sensible multivariate analysis of the contemporary data such as wind, waves and current. Three different cases are analyzed: i) the correlation of extremes of different variables (wind, wave and current), ii) the extreme profiles of current and iii) the current profile climate. A practical case study is illustrated throughout the paper.
5
Aung, Eighdi, Marco P. Schoen, and Jichao Li. "Dynamic Characterization and Identification of Flow in a Blade Passage in Near-Stall Conditions of Axial Compressor Systems." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-90998.
Повний текст джерелаАнотація:
Abstract Axial compressor systems are susceptible to unstable conditions near their optimal operating point. In particular, rotating stall and surge are conditions that need to be avoided during the operation of an axial compressor. In extreme cases these conditions may cause damage to the compressor. The onset of either condition is rather rapid, and usually does not allow for remedial control action based on the limited time available. Hence, research efforts have been focusing on the development of new detection methods that allow for more time to take corrective measures. This paper explores and compares various existing and proposed methods to identify and detect those precursors. The methods detailed in this work are tested at different operating conditions and locations. The methods investigated include the sequentially computed correlation coefficient of pressure sensor data, correlation coefficient, the Generalized Extreme Studentized Deviate Test (ESD) for outlier detection, spectral entropy, and Autoregressive (AR) models. The primary goal of evaluating these methods is based on their suitability for employment as pre-processors for dynamic system identification. By using the dynamics of the identified model rather than a static precursor, it is stipulated that the onset of stall and surge can be managed with a control concept. For this work, the extracted models are investigated for suitability to serve as precursors, and the potential as predictive models. This work may serve for future work to achieve active flow control by direct air injection at the leading edge of the blades. For this work, a one-stage compressor system with a blade geometry that allows for spike inception is utilized. Spike stall inception is a precursor to fully developed rotating stall. The subsonic compressor has 60 blades, and its operating point is controlled by a throttle and constant speed control of the rotor. The pressure data is collected with 10 Kulite™ sensors which are placed along the blade cord length on the outer casing of the compressor. The results of the tabulated performance of the various methods and resulting models indicate that an ARESD combination yields the earliest indication for spike stall inception.
6
Yeole, Parag Suresh, Eric Zilafro, Abhineet Gupta, and Chen Cheng. "Methodology to Design and Qualify Subsea Flowline Connection Systems to Improve Reliability." In Offshore Technology Conference. OTC, 2022. http://dx.doi.org/10.4043/31714-ms.
Повний текст джерелаАнотація:
Abstract The objective of this paper is to present a design and testing methodology to improve subsea connection system reliability by correlating the analysis and experimental data per the latest industry recommended practice. In most cases, a theoretical approach has been used to establish different load capacities; however, no good method has been established for monitoring critical components of the clamp style connection system to matchthe computer analysis. The result is a lack of confidence for scaling the connector design up or down or extrapolating the load capacity for different offshore scenarios. To improve on the historical approach, a new method has been developed that applies ASME section VIIIDivision 2 elastic and plastic analysis method to designing the core system capacity of asubsea flowline connector. To have full confidence that the critical components is within ASME code and functional requirements, several strain gauges, and Linear Variable Differential Transformers (LVDTs) are used to monitor data under various load cases to give confidence that this critical component of the subsea connector system is within ASME code and functional requirements. A good correlation between qualification physical test data from the data acquisition system (DAQ) and analysis results illustrates the functionality of the critical component of the connection system under different extreme loading cases. This method and process were used on Horizontal, Vertical,and Remotely Operated Vehicle (ROV)stab type connectors in alignment with API 17R "Recommended Practice (RP) for Flowline Connectors and Jumpers." The authors present the details of the design, verification, and validation process, and compare the data captured through the DAQ system with the finite element analysis (FEA) results. The satisfactory correlation between numerical methods and physical tests provides reliability in design and validation method to develop and qualify subsea flowline connection systems.
7
Gjika, Kostandin, and Chris Groves. "Nonlinear Dynamic Behavior of Rotor-Bearing Systems Involving Two Hydrodynamic Oil Films in Series: Prediction and Test Application to High-Speed Turbochargers." In ASME 8th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2006. http://dx.doi.org/10.1115/esda2006-95792.
Повний текст джерелаАнотація:
In recent years, the desire for increased engine performance has led to technology that increasingly relies on robust and reliable turbocharging solutions. The rotor-bearing system (RBS) operates under extreme oil conditions of low viscosity, high temperatures, low HTHS (high temperature high shear) value and low pressure, while the demand for maximum turbocharger speed and variable geometry technology continues to increase. The rotordynamics instability is a potential issue and the development of RBS is becoming a challenge for design optimization at the development stage. It is further complicated by a lack of industrial standards to guide design practices related to the dynamics and the effort to combine high performance with low cost. This paper concerns the progress on nonlinear dynamic behavior modeling of turbocharger rotor-radial bearing system with fully floating bearing design. A developed fluid dynamics code predicts bearing rotational speed, operating inner and outer bearing clearances, effective oil viscosity taking into account the shear effect and hydrostatic load. The data are input to a rotordynamics code which predicts nonlinear lateral response (total shaft motion) of the rotor-bearing system. The model is validated with a high speed turbocharger RBS of 7.9 mm journal diameter running up to 160,000 rpm (maximum speed) with oil 0W30, 100 °C oil inlet temperature and 4 bar oil feed pressure. The test is conducted on a rotordynamics technology cell. An advanced data acquisition system is implanted and a powerful code is developed for automated data reduction. Prediction/test data show good correlation with the respect of synchronous response and total motion. The predictive model helps the development of high performance RBS with faster development cycle times and increased reliability.
8
Svoboda, Jiří, and Vladislav Kocián. "Framework for Virtual and Physical Testing of Automated Vehicle Systems." In FISITA World Congress 2021. FISITA, 2021. http://dx.doi.org/10.46720/f2020-acm-046.
Повний текст джерелаАнотація:
Massive expansion and implementation of Advanced Driver Assistant Systems and advent of Highly Automated Driving functions brings huge challenges in terms of design and development, but also function validation and certification process which is a limiting factor for their market introduction. To ensure safety of such systems, whose complexity is rapidly growing, it is essential to evaluate functionality of automated driving systems within the mandatory certification before it’s deployed on the road. And after their deployment, they must be a subject to periodical technical inspection during life cycle as well. The number of regulations and standards considering safety of AD functions gradually increases, but current safety standards and regulations still have to be adopted and enhanced. For highly automated driving functions and AVs that do not require permanent monitoring by the driver, a theoretically infinite number of possible traffic situations, that a self-driving car could possibly encounter, needs be tested. One promising method to overcome this matter is the scenario-based approach focused on critical, dangerous and extreme situations. Such approach ensures a repeatability and robustness of an approval process if it is supported by a significant sample of harmonized scenarios. Since confronting conventional physical driving tests with this test effort is not feasible anymore, virtualization of testing methods by means of computer simulation needs to be emphasized. To meet above described challenges, TÜV SÜD is developing a methodology for scenario-based evaluation of AD functionality as a supplement for either development or future certification of automated driving systems. The methodology combines virtual-based approach and physical testing and guarantees repeatability of test conditions. Virtual-based testing is provided by an in-house simulation toolchain with an open architecture. The toolchain consists of functional blocks as: database of standardized scenario, virtual environment model, high fidelity physics-based sensor simulation, model of vehicle dynamics, control functions and algorithms, automated and standardized post-processing and reporting. Physical testing provides real-world data measurement used among other purposes for validation of the simulation toolchain and its relevant functional blocks respectively. Physical testing is performed on our own test track using typical equipment as: driving robots, inertial measurement unit, guided soft target, soft VRU targets, master control station and others. In presentation, an overview of the current state of methodology is given and the workflow is demonstrated for a specific operational design domain (ODD). Architecture of simulation toolchain is described and explanation how functional blocks are embedded into overall architecture and how they interact with each other is given. Trustworthiness for virtual test execution will be discussed by means of a comparison and correlation between real-world and virtual-simulation measurement results for a specific operational design domain.
9
Renton, Neill C., Paul Sicsic, and Joao Falcao Alegrias. "Loading Combination Screening Using Probabilistic Determination of Load-Case Matrices." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-61384.
Повний текст джерелаАнотація:
The application of probabilistic methods to determine the design of offshore systems such as jackets, ship hulls and pipelines is well developed and has a long and successful track record. While flexible risers are subjected to the same random environmental loads, probabilistic methods have yet to be applied in any meaningful way to the common limit states examined by the design community. Flexible riser systems offer operators a robust method of producing oil and gas fields in harsh environments. Systems are currently designed using a mixture of local and international standards such that they can withstand conditions with a sufficient margin of safety. Extreme dynamic analyses using proprietary finite element analysis (FEA) codes are performed using a deterministic load case matrix to define the extreme loading on the riser system. The loads are used to iterate the riser configuration / cross-section design to a fit-for-purpose solution and to define ancillary equipment, such as bend stiffeners, bend stiffener connectors, buoyancy modules and riser clamps. Individual load cases (LC) are defined by combining a number of parameters in order to represent different weather events and associated vessel responses in certain operating and accidental conditions, known as engineering events. LC matrices are then defined based on all combinations of weather and engineering events. However, the likelihood of the weather event or the engineering event occurring is currently not assessed. In the existing deterministic approach, all cases are run through the FEA model to validate the design criteria. However, increases in computing power have allowed load case matrices to expand by orders of magnitude as more variables and environmental conditions are considered. This has resulted in a large increase in engineering costs and capital expenditure through potentially over-designed solutions. This paper will demonstrate a new probabilistic screening assessment for developing a LC matrix for the dynamic analysis of flexible risers. Specifically, the combined wave and current loads on the flexible riser system in service are examined to determine the probability of occurrence of the weather event. ISO 13628-2 [1] currently states that load cases with a frequency of 1 in 10,000 years are non-credible for design purpose and can be ignored. The field metocean data including directional sea-states and likelihoods are used to confirm which weather events meet this criteria, screening out those which are non-credible. This screening reduces significantly the number of load combinations while validating a fit for purpose design. The correlation of environmental loads generated by wind, wave and currents is a complex topic, nevertheless, it is incorporated conservatively in the screening method developed in this study. An example is shown for the West-of-Shetland quadrant, where the methodology is applied to a designed riser system. The screening methodology shows 70% of the load cases have non-credible probabilities of occurrence of less than 2.0E−03 over 20 years (lower than one in 10,000 year annual frequency). The example also shows that the load cases which governed the design present a lower probability of occurrence than specified by the industry standards. The methodology removes complexity from the engineering system which could be directly converted into manufacturing and installation cost-savings.
10
Christopherson, Adam, and Young-Hoon Han. "Validation for External Tieback Connector Bending Capacity by Strain Measurement." In ASME 2019 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/pvp2019-93925.
Повний текст джерелаАнотація:
Abstract Strain gauges provide a convenient and affordable method to accurately measure the strain field for complex systems. Not only do they provide crucial information for predicting the fatigue life of components, but they can also determine the principle stresses which can be used to compare design factors with accepted industry standards. The use of electrical resistance strain gauges for load verification has become an ever-increasing practice in the design of subsea connectors as evidenced by the recent application in the industry guidance API 17TR7 [1]. The design is aided by the development of a Finite Element Analysis (FEA) which is used to predict the load capacities for normal, extreme, and survival conditions. The present work describes the experimental validation of a 18-3/4in 10,000 psi subsea collet connector model by applying linear pattern CEA-06-062UW-350 strain gauges at discrete points along the circumferentially spaced collet segments. The collet segments are the selected components for strain gauge placement because not only are they the primary connecting element between the subsea wellhead and the connector body, but they also only support axial loads. The axial strain of the collet segments in tension were compared at two combined loading cases: maximum bending capacity with and without internal working pressure and found to be in good correlation with the elastic-plastic FEA. The experimentally validated FEA is a crucial tool in determining the connector’s application to project or customer specific load and fatigue requirements and eliminates the need for unnecessary experimentation.
Звіти організацій з теми "Correlation-extreme systems"
1
Халік, Олена Олександрівна. Особливості образів батьківської та майбутньої сімейної системи у сучасних студентів жіночої статі та їх взаємозв’язок з рівнем перфекціонізму. Гнозис, 2015. http://dx.doi.org/10.31812/123456789/3791.
Повний текст джерелаАнотація:
У статті аналізуються особливості образів батьківської та майбутньої сімейних систем у сучасних студентів жіночої статі, визначаються збалансованість та незбалансованість вказаних родин. З’ясовано, що третина образів майбутньої родини є незбалансованими, з домінуванням заплутано-хаотичного типу. Встановлено зв’язок перфекціонізму спрямованого на інших та соціально обумовленого перфекціонізму з окремими показниками образу майбутньої сім’ї. This article deals with the analyze of the female students’ perceptions of their parental family and their own future family systems. Author determines the balanced and extreme families. It was found that a third of all perceptions of the future family are extreme, with the dominance of chaotically engaged type. It is proved that there are significant differences between the perceptions of the parental family and their own future family. It was found that the most of the female students choose a model of mid-range family, like their parental families are. There is the statistically significant positive correlation between the index of socially prescribed perfectionism conformism and emotional bonding, emotional ties, family boundaries, decision making and family time. There is a significant negative correlation between other-oriented perfectionism, family flexibility, and discipline in the family and relationship rules.
2
Heitman, Joshua L., Alon Ben-Gal, Thomas J. Sauer, Nurit Agam, and John Havlin. Separating Components of Evapotranspiration to Improve Efficiency in Vineyard Water Management. United States Department of Agriculture, March 2014. http://dx.doi.org/10.32747/2014.7594386.bard.
Повний текст джерелаАнотація:
Vineyards are found on six of seven continents, producing a crop of high economic value with much historic and cultural significance. Because of the wide range of conditions under which grapes are grown, management approaches are highly varied and must be adapted to local climatic constraints. Research has been conducted in the traditionally prominent grape growing regions of Europe, Australia, and the western USA, but far less information is available to guide production under more extreme growing conditions. The overarching goal of this project was to improve understanding of vineyard water management related to the critical inter-row zone. Experiments were conducted in moist temperate (North Carolina, USA) and arid (Negev, Israel) regions in order to address inter-row water use under high and low water availability conditions. Specific objectives were to: i) calibrate and verify a modeling technique to identify components of evapotranspiration (ET) in temperate and semiarid vineyard systems, ii) evaluate and refine strategies for excess water removal in vineyards for moist temperate regions of the Southeastern USA, and iii) evaluate and refine strategies for water conservation in vineyards for semi-arid regions of Israel. Several new measurement and modeling techniques were adapted and assessed in order to partition ET between favorable transpiration by the grapes and potentially detrimental water use within the vineyard inter-row. A micro Bowen ratio measurement system was developed to quantify ET from inter-rows. The approach was successful at the NC site, providing strong correlation with standard measurement approaches and adding capability for continuous, non-destructive measurement within a relatively small footprint. The environmental conditions in the Negev site were found to limit the applicability of the technique. Technical issues are yet to be solved to make this technique sufficiently robust. The HYDRUS 2D/3D modeling package was also adapted using data obtained in a series of intense field campaigns at the Negev site. The adapted model was able to account for spatial variation in surface boundary conditions, created by diurnal canopy shading, in order to accurately calculate the contribution of interrow evaporation (E) as a component of system ET. Experiments evaluated common practices in the southeastern USA: inter-row cover crops purported to reduce water availability and thereby favorably reduce grapevine vegetative growth; and southern Israel: drip irrigation applied to produce a high value crop with maximum water use efficiency. Results from the NC site indicated that water use by the cover crop contributed a significant portion of vineyard ET (up to 93% in May), but that with ample rainfall typical to the region, cover crop water use did little to limit water availability for the grape vines. A potential consequence, however, was elevated below canopy humidity owing to the increased inter-row evapotranspiration associated with the cover crops. This creates increased potential for fungal disease occurrence, which is a common problem in the region. Analysis from the Negev site reveals that, on average, E accounts for about10% of the total vineyard ET in an isolated dripirrigated vineyard. The proportion of ET contributed by E increased from May until just before harvest in July, which could be explained primarily by changes in weather conditions. While non-productive water loss as E is relatively small, experiments indicate that further improvements in irrigation efficiency may be possible by considering diurnal shading effects on below canopy potential ET. Overall, research provided both scientific and practical outcomes including new measurement and modeling techniques, and new insights for humid and arid vineyard systems. Research techniques developed through the project will be useful for other agricultural systems, and the successful synergistic cooperation amongst the research team offers opportunity for future collaboration.