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Auswahl der wissenschaftlichen Literatur zum Thema „Archer monté“
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Zeitschriftenartikel zum Thema "Archer monté"
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Wholey, Mark H. „ARCHER Trial: One-Month Results“. Journal of Vascular and Interventional Radiology 15, Nr. 2 (Februar 2004): P29. http://dx.doi.org/10.1016/s1051-0443(04)70069-x.
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Chouchene, Farah, Aymen Ben Haj Khalifa, Fatma Masmoudi, Ahlem Baaziz, Fethi Maatouk und Hichem Ghedira. „Dental Management of a Tunisian Child with Sanjad-Sakati Syndrome“. Case Reports in Dentistry 2022 (22.04.2022): 1–5. http://dx.doi.org/10.1155/2022/9585460.
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Sanjad-Sakati syndrome (SSS) is a rare autosomal recessive congenital disorder. The present case report is aimed at describing the orofacial manifestations and dental management of a 4-year seven-month-old, Tunisian boy with SSS. The patient has typical dysmorphic facial features and growth retardation. Intraoral examination revealed micrognathic mandible and maxilla, an arched palate, and small dental arches with an open bite. All the maxillary and mandibular teeth were decayed due to the poor oral hygiene, plaque accumulation, and enamel hypoplasia. Oral rehabilitation involved pulpotomies and root canal therapies on decayed teeth. Resin composite restorations were performed on maxillary and mandibular incisors, and stainless-steel crowns were placed on maxillary and mandibular first and second primary molars. Dental treatment of children with SSS should improve their quality of life and their general health. Undeveloped dental arches associated with dental anomalies as well as learning deficit make very difficult of the oral rehabilitation of such patients.
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Peng, Zhao, Yu Lu, Yao Xu, Yongzhe Li, Bo Cheng, Ming Ni, Zhi Chen et al. „Development of a GPU-accelerated Monte Carlo dose calculation module for nuclear medicine, ARCHER-NM: demonstration for a PET/CT imaging procedure“. Physics in Medicine & Biology 67, Nr. 6 (17.03.2022): 06NT02. http://dx.doi.org/10.1088/1361-6560/ac58dd.
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Abstract Objective. This paper describes the development and validation of a GPU-accelerated Monte Carlo (MC) dose computing module dedicated to organ dose calculations of individual patients undergoing nuclear medicine (NM) internal radiation exposures involving PET/CT examination. Approach. This new module extends the more-than-10-years-long ARCHER project that developed a GPU-accelerated MC dose engine by adding dedicated NM source-definition features. To validate the code, we compared dose distributions from the point ion source, including 18F, 11C, 15O, and 68Ga, calculated for a water phantom against a well-tested MC code, GATE. To demonstrate the clinical utility and advantage of ARCHER-NM, one set of 18F-FDG PET/CT data for an adult male NM patient is calculated using the new code. Radiosensitive organs in the CT dataset are segmented using a CNN-based tool called DeepViewer. The PET image intensity maps are converted to radioactivity distributions to allow for MC radiation transport dose calculations at the voxel level. The dose rate maps and corresponding statistical uncertainties were calculated at the acquisition time of PET image. Main results. The water-phantom results show excellent agreement, suggesting that the radiation physics module in the new NM code is adequate. The dose rate results of the 18F-FDG PET imaging patient show that ARCHER-NM’s results agree very well with those of the GATE within −2.45% to 2.58% (for a total of 28 organs considered in this study). Most impressively, ARCHER-NM obtains such results in 22 s while it takes GATE about 180 min for the same number of 5 × 108 simulated decay events. Significance. This is the first study presenting GPU-accelerated patient-specific MC internal radiation dose rate calculations for clinically realistic 18F-FDG PET/CT imaging case involving autosegmentation of whole-body PET/CT images. This study suggests that the proposed computing tools—ARCHER-NM— are accurate and fast enough for routine internal dosimetry in NM clinics.
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Xu, X. George, Tianyu Liu, Lin Su, Xining Du, Matthew Riblett, Wei Ji, Deyang Gu et al. „ARCHER, a new Monte Carlo software tool for emerging heterogeneous computing environments“. Annals of Nuclear Energy 82 (August 2015): 2–9. http://dx.doi.org/10.1016/j.anucene.2014.08.062.
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Hidayah, Rahmatul, Siti Khadijah Harahap, Risda Kesuma Lubis, Rizka Junita, Lili Nurindah Sari und Khairul Khairul. „Monitoring the Biological Aspects of Banded Archer Fish (Toxotes jaculatrix Pallas, 1767) in Bilah River, Labuhanbatu Regency, Indonesia“. Jurnal Penelitian Pendidikan IPA 9, Nr. 2 (28.02.2023): 676–80. http://dx.doi.org/10.29303/jppipa.v9i2.2321.
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Banded archer fish (Toxotes jaculatrix Pallas, 1767) is one of the leading commodities of Indonesian ornamental fish. Its production so far is still from the catch of nature. Banded archer fish based on IUCN data has been included in the red list with the Least Concern (LC) category. Currently one of its habitats is found in the Bilah River, Labuhanbatu Regency. The purpose of the study was to information the condition of biological factors related to the relationship of weight length, sex ratio and factors of banded archer fish conditions in the Bilah River. Determination of observation station points by purposive sampling method, where in this study there are 3 stations. Fish sampling in January-March 2022. Fish are caught using splint nets. The entire number of fish caught was measured using a ruler with a length of 30 cm and weight using a digital balance sheet with a precision of 0.01 g. Next the data is tabulated and analyzed using the Microsoft Excel 2013 application. The data of the results of the study is displayed based on each month of observation. The results of the analysis of banded archer fish research data for the long weight relationship from January-March 2022 are negative alometric. The sex ratio of banded archer fish in January 2022 (0.69:1), February 2022 (0.47:1), and March 2022 (0.5:1). The value of the banded archer fish condition factor in January 2022 (1.0304), February 2020 (1.0338), and March 2022 (0.0954). It was concluded that the biological aspects of banded archer fish in the Bilah River still their growth and reproductioan.
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Kaium, Abdullah Al, Shamim Shamsi, Md Almujaddade Alfasane und Md Abul Bashar. „New Records of Lichens from Khadimnagar National Park Sylhet, Bangladesh. I.“ Bangladesh Journal of Plant Taxonomy 30, Nr. 2 (24.12.2023): 175–83. http://dx.doi.org/10.3329/bjpt.v30i2.70494.
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An investigation was carried out from January 2021 to December 2022 to study the lichen flora of Khadimnagar National Park. The present paper deals with 10 new records of lichens, namely, Acanthothecis asprocarpa (A.W. Archer) A.W. Archer, Bacidia absistens (Nyl.) Arnold, Caloplaca cinnabarina (Ach.) Zahlbr., Coenogonium implexum Nyl., Dirinaria leopoldii (Stein) D. D. Awasthi, Echinoplaca campanulata Kalb & Vězda, Metamelanea umbonata Henssen, Pyrgillus javanicus (Mont. & Bosch) Nyl., Ramboldia blastidiata Kantvilas & Elix and Trypethelium ochroleucum (Eschw.) Nyl. Detailed taxonomic description of the newly reported species with photographs are provided. Bangladesh J. Plant Taxon. 30(2): 175-183, 2023 (December)
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Nguyen, Τ. Η. „Global Sensitivity Analysis Of In-Plane Elastic Buckling Of Steel Arches“. Engineering, Technology & Applied Science Research 10, Nr. 6 (20.12.2020): 6476–80. http://dx.doi.org/10.48084/etasr.3833.
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Steel arches are widely used in civil engineering and industrial structures. Their response depends on material properties, geometric dimensions, and boundary conditions. The objective of the current study is to perform global sensitivity analysis and to assess the influence of random input parameters on the in-plane elastic buckling of steel arches. The in-plane elastic buckling load of steel arches under uniform compression proposed in previous studies is adopted. The influence of the random input variables of the structure is evaluated using Sobol’s global sensitivity analysis. Monte Carlo simulation is also employed to rank the influence of input random variables.
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Turatti, G., A. Bruni, M. Savoini, M. Giordano und G. Gerbino. „Maxillomandibular Transverse Osteodistraction: A Multidisciplinary Case Report with 30-Month Follow-Up“. Case Reports in Dentistry 2020 (01.02.2020): 1–11. http://dx.doi.org/10.1155/2020/3856412.
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Aim. To describe a multidisciplinary treatment to correct a severe II class malocclusion with reduced both maxillary and mandibular transverse dimensions and dental crowding. Case Report. A 17-year-old young woman presented with an increased overjet complaining chiefly of forwardly placed upper front teeth and unpleasant smile aesthetics. The patient facially exhibited a gently convex profile, severe mentalis strain on lip closure, and dark buccal corridors. The intraoral assessment indicates Class II molar relationship bilaterally, mandibular and maxillary anterior crowding, and narrow shape of upper and lower arches. The cephalometric evaluation of the lateral radiograph of the skull evidences a skeletal Class II with a reduction of lower face height. Based upon the diagnostic records and consultation with the patient, surgically assisted expansion of both arches using bone-borne distractors, comprehensive orthodontic treatment, and combined jaw surgery was planned. Results. This approach permitted achieving most of the desired objectives in approximately 30 months. The follow-up records 30 months after treatment conclusion showed a stable occlusion. No complications were clinically and radiographically noticeable during the follow-up.
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Caglayan, Günhan. „Archetypal Mathematics“. Mathematics Teacher 106, Nr. 8 (April 2013): 574–78. http://dx.doi.org/10.5951/mathteacher.106.8.0574.
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Melnick, Jorge. „Markov Chain Monte-Carlo Models of Starburst Clusters“. Proceedings of the International Astronomical Union 9, S307 (Juni 2014): 123–24. http://dx.doi.org/10.1017/s1743921314006498.
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AbstractThere are a number of stochastic effects that must be considered when comparing models to observations of starburst clusters: the IMF is never fully populated; the stars can never be strictly coeval; stars rotate and their photometric properties depend on orientation; a significant fraction of massive stars are in interacting binaries; and the extinction varies from star to star. The probability distributions of each of these effects are nota prioriknown, but must be extracted from the observations. Markov Chain Monte-Carlo methods appear to provide the best statistical approach. Here I present an example of stochastic age effects upon the upper mass limit of the IMF of the Arches cluster as derived from near-IR photometry.
Bücher zum Thema "Archer monté"
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Rowling, James. Archery Calendar 2022-2023: Official Planner Archery Calendar 2022 - 2023 Monthly Weekly and Daily Archery Calendar 2022 with Notes, 18 Month Square Archery Calendar 2023. Independently Published, 2021.
Den vollen Inhalt der Quelle findenBuchteile zum Thema "Archer monté"
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Dumas, Alexandre. „The Little Room in the Tuileries“. In The Count of Monte Cristo. Oxford University Press, 2008. http://dx.doi.org/10.1093/owc/9780199219650.003.0011.
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We will leave Villefort on the road to Paris, travelling with all speed, and penetrate the two or three apartments which precede it, then enter the small cabinet of the Tuileries with the arched window, so well known as having been the favourite bureau...
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Engle, Robert F., und Gloria Gonzalez-Rivera. „Semiparametric ARCH Models“. In Arch, 114–44. Oxford University PressOxford, 1995. http://dx.doi.org/10.1093/oso/9780198774310.003.0006.
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Abstract This article introduces a semiparametric autoregressive conditional hetero scedasticity (ARCH) model that has conditional first and second moments given by autoregressive moving average and ARCH parametric formulations but a conditional density that is assumed only to be sufficiently smooth to be approximated by a nonparametric density estimator. For several particular conditional densities, the relative efficiency of the quasi-maximum likelihood estimator is compared with maximum likelihood under correct specification. These potential efficiency gains for a fully adaptive procedure are compared in a Monte Carlo experiment with the observed gains from using the proposed semiparametric procedure, and it is found that the estimator captures a substantial proportion of the potential. The estimator is applied to daily stock returns from small firms that are found to exhibit conditional skewness and kurtosis and to the British pound to dollar exchange rate.
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Cunningham, Carol, und Joel Berger. „Rhino Rhetoric“. In Horn of Darkness, 217–24. Oxford University PressNew York, NY, 1997. http://dx.doi.org/10.1093/oso/9780195111132.003.0028.
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Abstract January snow blanketed northern Nevada as we prepared for a fourth field season. Despite sunny blue skies, high temperatures hovered near 20°F. We visited physicians, dentists, and accountants, and each day stacked supplies in our living room. We also bought last-minute items for Namibian friends-gun parts, a camera, a day pack and tent for Archie, a book on elephant lore for Malan. But there was still no one to housesit or care for the dogs. Airlines in the United States, Europe, and South Africa had yet to decide on charges for our excess baggage. Even getting to Los Angeles International Airport would be difficult because of the massive freeway destruction from the devastating earthquake only a week earlier. One thing kept worrying us-the six-month silence from Namibian officials.
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Morrison, Louise, und Brian A. McCrossan. „Cardiac evaluation of a child with stridor“. In Challenging Concepts in Congenital and Acquired Heart Disease in the Young, 237–46. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198759447.003.0018.
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This is the case of a 6-month-old boy who is diagnosed with, and treated for, a vascular ring, following several admissions to paediatric intensive care with difficult respiratory symptoms and ongoing failure to thrive. This case highlights the diagnostic challenge presented by these patients. Cardiovascular causes of paediatric airway compression are often under-recognized, with consequent delay in diagnosis. Although they are much less common than other causes of stridor, such as laryngomalacia or other tracheo-bronchial anomalies, chronic airway compression in childhood from vascular malformations carries significant morbidity and mortality. It is readily treatable and should not be overlooked. A high index of suspicion for mechanical compression should be maintained in small children with recurrent obstructive respiratory signs and symptoms or the older child presenting with dysphagia. The most prevalent vascular anomalies resulting in airway compression are a double aortic arch, right aortic arch with an aberrant left subclavian artery, innominate artery compression, left aortic arch with an aberrant right subclavian artery (rarely), and pulmonary artery sling. Rarely, complex congenital heart disease, itself leading to dilatation of the cardiac structures, may precipitate airway compromise, as in tetralogy of Fallot with an absent pulmonary valve syndrome or conditions with significant atrioventricular valve regurgitation causing left atrial enlargement. A dilated ascending aorta may compress the trachea, producing similar symptoms likewise with a cervical aortic arch with an aberrant sublclavian artery and ipsilateral ligamentum arteriosus. Such cases require a comprehensive diagnostic workup. Investigations include plain chest X-ray, echocardiogram, direct microlaryngoscopy and bronchoscopy, and CT angiography or cardiac MRI. A normal laryngoscopic examination should warrant further investigation in the presence of ongoing symptoms. An appreciation of aortic arch embryology is important in interpreting echocardiography and cross-sectional imaging in relation to the role of airway compression. Management often necessitates multidisciplinary collaboration among specialties, including ear, nose, and throat (ENT) specialists, paediatric cardiologists, respiratory physicians, intensivists, and cardiothoracic surgeons. Definitive treatment depends on the underlying pathology but usually involves surgical decompression or aortopexy. A proportion of patients will continue to exhibit symptoms following surgical release, due to ongoing weakness of the airway, and in severe cases may require ongoing respiratory support.
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Declercq, Georges. „Un produit de l’école et du scriptorium.. L'acte privé à l'abbaye de Saint-Pierre-au-Mont-Blandin au Xe et XIe siècle“. In Archiv für Diplomatik, Schriftgeschichte, Siegel- und Wappenkunde, 285–324. Böhlau Verlag, 2023. http://dx.doi.org/10.7788/9783412529369.285.
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Sett, Kiranjit, und Debabrata Mukhopadhyay. „The Role of Market Sentiment in Stock Price Movements“. In Handbook of Research on Globalization, Investment, and Growth-Implications of Confidence and Governance, 24–43. IGI Global, 2015. http://dx.doi.org/10.4018/978-1-4666-8274-0.ch002.
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In an efficient capital market, the prices of securities always fully reflect all available information implying that prices always reflect the fundamental values. When there is under reaction or over reaction to new information, competition among the arbitrageurs quickly brings the price of an asset back to its fair value. But, if the asymmetry of information about a stock is high and there is a ‘limit to arbitrage', sentiment of the noise traders is likely to influence the price of that stock. This chapter aims at studying the role of market sentiment, during the period which starts with June 2003 and ends with July 2011, in influencing the return from investment in small capitalization stocks listed on Indian stock exchanges. We have found the presence of ARCH (1) in the time series on returns. Market sentiment, rate of interest and inflation are found to have significant influence on return from investment in small capitalization stocks. The presence of month effects in returns from such stocks has also been detected.
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Miller, Jacob C. „Retail Ruins“. In Retail Ruins, 38–88. Policy Press, 2023. http://dx.doi.org/10.1332/policypress/9781529225532.003.0003.
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This chapter examines vacant sites around Newcastle upon Tyne’s city centre to consider the possibility of retail ruins. Using photographs taken by the author, the chapter fuses them with other observational data collected over a 12-month period (2021–22). Using a montage approach, this material weaves together a photo essay with a philosophical arch between Benjamin’s dialectics and Derridean hauntology. This move can help us avoid pitfalls in understanding dialectics as an appropriate framework for analysis, particularly for issues concerning consumption and retail. The chapter focuses a microscope on these void-like spaces whose negative energies seep into the urban atmosphere. Their qualities deserve attention as unwitting agents in the production of atmosphere, tinging it all with a spookiness that runs down our spines when confronted with the ghost. For that reason, a montage approach allows for a consideration of specific ideas and themes, though without synthesizing them into a singular summary of what they might mean. As an anti-totalitarian methodology, it leaves space for readers to think for themselves.
Konferenzberichte zum Thema "Archer monté"
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George Xu, X., Tianyu Liu, Lin Su, Xining Du, Matthew Riblett, Wei Ji, Deyang Gu et al. „ARCHER, a New Monte Carlo Software Tool for Emerging Heterogeneous Computing Environments“. In SNA + MC 2013 - Joint International Conference on Supercomputing in Nuclear Applications + Monte Carlo, herausgegeben von D. Caruge, C. Calvin, C. M. Diop, F. Malvagi und J. C. Trama. Les Ulis, France: EDP Sciences, 2014. http://dx.doi.org/10.1051/snamc/201406002.
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Boyd, Iain. „Monte Carlo simulation of hydrogen arcjet flow fields“. In 32nd Joint Propulsion Conference and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1996. http://dx.doi.org/10.2514/6.1996-3297.
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BOYD, IAIN, MARK CAPPELLI und DOUG BEATTIE. „Monte Carlo and experimental studies of nozzle flow in a low-power hydrogen arcjet“. In 29th Joint Propulsion Conference and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1993. http://dx.doi.org/10.2514/6.1993-2529.
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GOGEL, T., A. SEDGHINASAB und D. KEEFER. „Calculation of arcjet constrictor plasma temperatures using a Monte Carlo method for radiation transfer“. In 21st International Electric Propulsion Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1990. http://dx.doi.org/10.2514/6.1990-2615.
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Ying Kwan, Mei, Kit Lun Yick, Joanne Yip und Chi Yung Tse. „Intervention of arch support: A quantitative study“. In 13th International Conference on Applied Human Factors and Ergonomics (AHFE 2022). AHFE International, 2022. http://dx.doi.org/10.54941/ahfe1002593.
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Hallux valgus is a common foot deformity characterized by hypermobility of the first metatarsal ray. The lower longitudinal arch is an intrinsic factor related to the lateral drift of the hallux. This paper conducted a quantitative study on the improvement of the first metatarsal and arch condition by arch support and used finite element analysis to simulate the bone displacement with the intervention of arch support. In this research, a foot arch support made of carbon fiber was developed and seventy-six female subjects were recruited for a two-month wear trial. Footprints of their dominant foot were measured to investigate the effect of the arch support on lifting the arch and correcting the hallux valgus pathology. Different foot parameters including foot length, foot breadth, heel breadth, arch angle, arch breadth, plantar arch index, foot type index, and hallux valgus angle were also compared. By using finite element analysis, the biomechanical effects of the arch support on the foot structure can be visualized. According to the results of the wear trial, the use of the arch support can significantly improve the arch curvature of the foot, while no significant correction of the hallux valgus angle was found. Among the arch parameters, the arch breadth and the foot type index are the key indicators to precisely characterize foot types and arch conditions. When a clear outline of the footprint is not available, arch breadth provides reliable association with the foot type index (R2 = 0.928). An arch breadth ≥ 4 cm is categorized as flatfoot. This article confirms the effectiveness of our arch support in lifting the arch over a two-month period and provides a scientific surrogate index to aid in diagnosis, which is important for therapeutic and diagnostic applications.
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Acciarini, Giacomo, Nicola Baresi, David Lloyd und Dario Izzo. „Stochastic Continuation for Space Trajectory Design“. In ESA 12th International Conference on Guidance Navigation and Control and 9th International Conference on Astrodynamics Tools and Techniques. ESA, 2023. http://dx.doi.org/10.5270/esa-gnc-icatt-2023-198.
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Designing and planning periodic orbits in an uncertain environment can be very challenging. Traditionally, trajectories are engineered in a two-step approach. First, nominal orbits are designed, describing the system as a deterministic dynamical model. Then, brute-force Monte Carlo simulations are used to test the initial conditions against model uncertainties and knowledge errors (e.g. imprecise estimation of the spacecraft state). While this approach constitutes the de facto standard in current space trajectory design practices, it leads to very time consuming and potentially suboptimal solutions, due to the fact that the robustness of candidate orbits is only assessed a-posteriori. In this work, we propose a paradigm shift accounting uncertainties from the very early design phases. In particular, our aim is to study the low-order moments of the satellites’ probability density functions of the state extending numerical continuation techniques to stochastic scenarios. Numerical continuation for deterministic systems is a widely known and used method to find and continue equilibria, periodic orbits or tori in dynamical systems [1]. More recently, stochastic continuation techniques have been proposed as an alternative to these traditional methods to allow the continuation of the low-order moments of probability density functions in uncertain environments, by calculating the fixed points of the first moments (e.g. mean and covariance) of the uncertain parameters [2]. While these techniques have shown to be successful for some dynamical systems [3,6], they have never been applied to the complex and rich dynamical environments of the circular restricted three-body problem. Moreover, they still rely on traditional Monte Carlo approaches to integrate ensembles of initial conditions and estimate the moments to be continued: this can become quite challenging in terms of computational costs for highly nonlinear dynamics, long time horizons, or higher moments. With this work, our goal is to show the potential beneficial application of stochastic continuation to space mission design and how it can be leveraged to incorporate uncertainties from the early design stages. We modify the standard differential correction procedure used to find fixed points of deterministic Poincare’ mappings by using the Newton-GMRES method: this allows to estimate the Jacobian-vector product for systems in which the analytical expression of the Jacobian is not available [6], as it is the case for the first moments of the uncertain parameters. To alleviate the computational complexity of stochastic continuation techniques, we also show two different approaches to propagate the initial state uncertainties at future times, discussing their merits and drawbacks. First, we use a fast Taylor propagator to numerically integrate the samples of the distribution and reconstruct the propagated uncertainties at future times [7]. Furthermore, we also use differential algebra techniques to build and quickly evaluate high-order Taylor polynomial expansions of Poincare’ mappings as a function of the random variables [8], thereby bypassing the use of Monte Carlo-based approaches to evolve the uncertainty at future times. We will discuss some preliminary experiments focused on adapting and improving stochastic continuation techniques to find fixed points of the Poincare’ mappings of the moment map in the planar circular restricted three-body problem (PCR3BP). We assume that the initial conditions of the state are random variables, whose probability density function is a multivariate Gaussian (e.g. due to tracking errors). We then first find the fixed points of both the mean and covariance of the distributions and later continue their values as a function of model parameters. Considering Distant Retrograde Orbits (DROs) in the Earth-Moon system as a test case scenario, we show how these solutions find regions of the phase space where the spacecraft would stay in a bounded region for time scales that comply with mission phases and requirements, thereby enabling the design of trajectories that are robust against uncertainties. We also discuss how stochastically continued trajectories differ from their deterministic counterparts, thereby quantifying the sub-optimality of the current a-posteriori design process. By combining dynamical system theory techniques with state-of-the-art computing and differential algebra advancements, we propose a first of its kind application of stochastic continuation techniques for mission design and analyses, showing its preliminary results for the PCR3BP of the Earth-Moon system. [1] R Seydel, "Practical Bifurcation and Stability Analysis", Springer Science & Business Media, 2009; [2] D Barkley, IG Kevrekidis, and AM Stuart, "The Moment Map: Nonlinear Dynamics of Density Evolution via a Few Moments", SIAM Journal of Applied Dynamical [3] CT Kelley, "Iterative Methods for Solving Linear and Nonlinear Equations", SIAM Publications, 1995; [4] C Willers, U Thiele, A Archer, DJB Lloyd, and O Kamps, "Adaptive stochastic continuation with a modified lifting procedure applied to complex systems", Physical Review E 102, 032210 (2020). DOI: 10.1103/PhysRevE.102.032210; [5] SA Thomas, DJB Lloyd, and AC Skeldon, Equation-free analysis of agentbased models and systematic parameter determination. Physica A: Statistical Mechanics and its Applications, Volume 464, Pages 27–53 (2016). DOI: 10.1016/ j.physa.2016.07.043; [6] C Willers, U Thiele, A Archer, DJB Lloyd, and O Kamps, "Adaptive stochastic continuation with a modified lifting procedure applied to complex systems", Physical Review E 102, 032210 (2020). DOI: 10.1103/PhysRevE.102.032210; [7] Biscani, Francesco, and Dario Izzo. "Revisiting high-order Taylor methods for astrodynamics and celestial mechanics." Monthly Notices of the Royal Astronomical Society 504.2 (2021): 2614-2628. [8] N Baresi, X Fu, R Armellin, “A high-order Taylor polynomial approach for continuing trajectories in three-body problems”, AAS/AIAA Astrodynamics Specialist Conference, 2020; Available Online;
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Liu, J. L., Y. Qian, K. Itatani, T. Miyakoshi, A. Murakami, M. Ono, R. Shiurba, K. Miyaji und M. Umezu. „An Approach of Computational Hemodynamics for Cardiovascular Flow Simulation“. In ASME-JSME-KSME 2011 Joint Fluids Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajk2011-03057.
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Computational fluid dynamics (CFD) is one of available methods to quantitatively evaluate the treatments of cardiovascular disease. However, currently, applications of this technology to cardiac surgery are few due to the complexity of performing physiological simulation. Here, we used CFD to study the outcome of the Norwood surgical procedure for palliating hypoplastic left heart syndrome in a 33-month-old child. The Reynolds number for post-surgical flow calculated at the peak of systole was about 4000, consistent with turbulent flow. During diastole, by contrast, the flow reduced to low speed, suggesting the strong transition flow from systole to diastole. Therefore, to improve the simulation of transitional flow, we determined that time step intervals of 10−5 second were best in using the k–ε turbulence model. We also develop a new boundary condition to simulate blood pressure wave reflection from peripheral vessels in order to physiologically capture pressure recovery and correctly obtained flow through each arch-branch and flow pattern in the coronary. Then we computed time-varying energy losses, local pressure, and wall shear stress at the anastomosis to evaluate the surgical outcome. The results suggest the time step and boundary conditions that take account of pressure wave reflection improve simulation of cardiovascular flow.
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BRENNER, CHRISTOPH, KLAUS THIELE und JULIAN UNGLAUB. „A REDUCED-ORDER DIGITAL TWIN FOR STRUCTURAL HEALTH MONITORING OF STEEL BRIDGES“. In Structural Health Monitoring 2023. Destech Publications, Inc., 2023. http://dx.doi.org/10.12783/shm2023/36798.
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Conventional simulation methods, such as the Finite Element method, are less suitable for efficient and adaptive digital twins of large-scale structures needed for structural health monitoring (SHM). The complexity and scale of such structures require new simulation techniques that can handle the increasing computational demands and provide accurate results in real-time. This paper presents a novel approach for the implementation of a digital twin for SHM of steel bridges using reduced order modelling. For this purpose, the commercial software Akselos originally developed for digital twining in the aerospace industry is herein adapted to a structural engineering context. The parametric and component-based approach allows a modular structure of the digital twin with the possibility for quick adaptions according to the SHM data. The method is applied to a steel arch bridge as a case study. The example bridge was monitored over the period of a month using strain gauges at five critical locations together with temperature sensors. In addition, a targeted loading test with a truck was performed. The collected monitoring sensor data is processed and merged into the digital twin. This integration enables precise predictions about the bridge’s structural integrity, maintenance and repair planning as well as possible future damage locations. The proposed approach demonstrates the potential of the digital twin for real-time monitoring and prediction of changes in the structural integrity of large-scale structures, providing a promising solution for efficient and effective SHM of steel bridges.
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Llorente-Martinez, Salvador, Alfredo Agenjo, Raul Sanchez-Maestro, Lex Meijer, Massimiliano Saponara, Carole Rosso und Francesco Cacciatore. „Performance achievement and verification of unprecedented stability AOCS for EUCLID“. In ESA 12th International Conference on Guidance Navigation and Control and 9th International Conference on Astrodynamics Tools and Techniques. ESA, 2023. http://dx.doi.org/10.5270/esa-gnc-icatt-2023-226.
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Euclid is an ESA medium class cosmology mission dedicated to the investigation of the properties of Dark Energy and Dark Matter. The mission will operate in a large Quasi-Halo orbit around the Sun-Earth Lagrangian point L2 about 1.5 million km away from the Earth. The scientific objectives of this mission impose challenging requirements on the system performances, arriving to levels of pointing stability of 75 milli-arcsec (99.7% confidence level) within periods of 700 seconds. The AOCS for this mission requires a very specific and advanced design, with incorporation of dedicated state-of-the-art attitude sensors and actuators. The achievement of those levels of stability mandate a quite special combination of units and dedicated sequence of operation, resulting in a delicate architectural organisation, and specific determination and control process, including several configurations of Attitude Determination functions, organised in an AOCS architecture which includes three organisation levels: modes, submodes and states. The resulting AOCS Application SW(AASW) is split into one part that is manually coded and one part that is auto-coded from the AOCS Guidance, Navigation, and Control (GNC) design models. The AASW interfaces only with the service framework and the math library of the Central ASW (CASW). Model Based Design (MBD) and Autocoding has been used, allowing an agile development and adjustment when needed. A dedicated process has been followed for the AOCS verification, involving a staggered verification from the design environment, up to the qualification in the Avionics Model (AVM) and acceptance in the Proto-Flight Model (PFM). In terms of performance verification, the verification starts with an extensive usage of the Engineering Simulator Environment (ESE). ESE is a High Fidelity Simulator including all the performance-relevant effects in the AOCS chain, and in particular, properly validated models for the AOCS units and the environment, including the GNC SW (Model-in-the-Loop) to be applied later in the construction of the OBSW. AOCS verification in ESE includes a combination of worst cases and Monte Carlo approaches, allowing a complete confirmation that the design and implementation of the GNC SW complies with the demanding performance requirements. From this solid starting point, the AOCS requirements are later verified with the complete On-Board SW (OBSW) and incorporating the operational environment, in the so-called SW Verification Facility (SVF). In this SVF the results obtained in the ESE environment are confirmed to be fully equivalent with the ones obtained in SVF. SVF is later complemented and confirmed for relevant aspects in a HW Computer in the Loop facility (HILF). Here all the electrical interfaces to/from the computer are generated/acquired by the AOCS-SCOE (Special Check-Out Equipment). A similar AOCS-SCOE is also applied by the spacecraft prime in the SC AVM and spacecraft PFM. The proposed paper will provide the logic, organisation and description of the verification process, including the verification of the performance in ESE and the confirmation within SW and HW environments. The application of the MBD and autocoding techniques will be addressed, with consideration of the measures taken to ensure equivalence of results after AASW integration into the complete OBSW and moving to the HW environments. SENER is the overall responsible and prime contractor of the Euclid AOCS, with Airbus Defence and Space Netherlands as main partner, while more than 7 additional direct subcontractors are contributing to different components of the subsystem. Thales Alenia Space Italy is Euclid prime contractor and AOCS customer.