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- Korobenko, Larysa, 1964-
(författare)
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Шведская коллекция славянских пергаменных фрагментов : Кодикологическое и палеографическое исследование
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation carries out a codicological and palaeographic investigation of Slavic parchment fragments taken from Russia to Sweden as war booty during a period of Swedish-Russian cultural interactions and military conflicts in the late 16th – early 17th centuries. The fragments in question were kept in Sweden until the beginning of the 19th century and mostly used as accounting binders. After 1809, some accounting records of Finnish territories (along with their parchment covers) were transferred from Sweden to Finland. Among them were accounting records with Slavic covers. In Finland, the parchment covers were removed from the accounting books and administrative documents that they had enclosed and sent to the University Library in Helsinki (now the National Library of Finland). In 1869, the Slavic fragments stored in Finland were donated to the Russian Academy of Sciences in St. Petersburg and then preserved in the Academy’s library (BAN, collection “Finliandskie otryvki”). Two Slavic fragments later came to England with George Stephens’ collection. Thus, the Slavic fragments are now held in archives, libraries and museums in four countries (Sweden, England, Finland and Russia). I use the designation The Swedish Collection of Slavic Parchment Fragments to refer to these four collections, once preserved in Sweden as part of a larger Swedish collection (the largest collection of medieval parchment fragments in Europe).All the parchment fragments belonging to the Swedish collection are undated, i.e. they have no inscriptions or additional information about the scribe, owner or patron, which would make it possible to immediately establish the time and place of their creation. This circumstance determined my choice of method for the analysis of the preserved fragments. They are studied in a comprehensive manner that combines codicological, palaeographic, historical and linguistic analysis. This has made it possible to pursue the study of the fragments in different directions, and to obtain the new specific and more general results presented in this dissertation.The palaeographic method of identifying scribes on the basis of their handwriting enabled me to connect different fragments with each other as well as with comparative manuscripts, and to determine their origins in the Mediaeval scriptoria of ancient Rus′: they were produced not only in Novgorod, but also in Pskov, Rostov and Moscow.
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| 2. |
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| 3. |
- Banerjee, Avijit, et al.
(författare)
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On the Design, Modeling and Experimental Verification of a Floating Satellite Platform
- 2022
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Ingår i: IEEE Robotics and Automation Letters. - : IEEE. - 2377-3766. ; 7:2, s. 1364-1371
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Tidskriftsartikel (refereegranskat)abstract
- In this letter, a floating robotic emulation platform is presented with an autonomous maneuverability for a virtual demonstration of a satellite motion. Such a robotic platform design is characterized by its friction-less, levitating, yet planar motion over a hyper-smooth surface. The design of the robotic platform, integrated with the sensor and actuator units, is briefly described, including the related component specification along with the mathematical model, describing its dynamic motion. Additionally, the article establishes a nonlinear optimal control architecture consisting of a unified model predictive approach for the overall manoeuvre tracking. The efficacy of the proposed modeling and control scheme is demonstrated in multiple experimental studies, where it is depicted that the proposed controller has the potential to address a precise point-to-point manoeuvre with terminal objectives, as well as an excellent path following capability. The proposed design is validated with extensive experimental studies, and it is supported with related results.
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| 4. |
- Bodin, Per-Arne, et al.
(författare)
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The Life of a Non-existent Ballet. Mjasin and Gončarova’s Liturgie
- 2021
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Ingår i: Slovo. - Uppsala : Uppsala universitet. - 2001-7359. ; 62, s. 8-24
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Tidskriftsartikel (refereegranskat)abstract
- The Ballets Russes piece Liturgie (1915) was rife with radical conceptions of dance, costume design and the aesthetics of performance. But Liturgie never existed in any other than an unfinished, fragmentary form; a concept of a ballet that never came to a premiere. The aesthetic use of religious imagery in Natalia Gončarova’s designs and the gesture-based movement material for Liturgie brought out the transformative potential of performance, but were, ultimately, impossible to become a reality on stage. In the article we use the notion of liminality to scrutinize the complex relation between the sketches and the outline of the choreography as well as the relation between the artistic and religious modes.
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| 5. |
- Satpute, Sumeet G., 1987-, et al.
(författare)
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Cooperative planning for multi-site asteroid visual coverage
- 2021
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Ingår i: Advanced Robotics. - : Taylor & Francis. - 0169-1864 .- 1568-5535. ; 35:21-22, s. 1332-1346
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Tidskriftsartikel (refereegranskat)abstract
- This article proposes a novel two-staged trajectory planning algorithm toward the cooperative visual coverage of multiple asteroid sites with the utilization of multiple spacecraft. The objective of the novel established planning scheme is to determine an observation tour for each spacecraft and the associated fuel optimal trajectories, such that each site of interest is observed only once during the entire mission. The completion of the observation task of an asteroid site is limited to the observation time window, referred as the period for which a site is illuminated by the Sun. The proposed planning algorithm divides the overall multi-site coverage problem into a nonlinear and integer optimization problem as: (i) a single target optimization and (ii) a multi-target multiple spacecraft optimal sequencing problem. The first part aims to generate fuel optimal trajectories, for all the initial-final imaging site location pairs. In the second part, the problem of distributing the observation task, among the fleet of spacecraft, is addressed by designing a feasible tour to observe a subset of the desired asteroid sites, for each spacecraft, while considering their individual fuel capacity. The efficacy of the proposed algorithm is evaluated in multiple simulation scenarios and while considering different asteroids.
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| 6. |
- Satpute, Sumeet Gajanan, 1987-
(författare)
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Guidance and Control for Multiple Spacecraft Formation
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Multiple spacecraft formation forms a distributed space system where multiple spacecraft cooperatively exhibit the functionality of a single monolithic spacecraft or work in a cooperative way towards the completion of a common goal. This possibility of distributing the workload between different spacecraft provides the ability to work in parallel, enable economic and simple solutions in terms of spacecraft design, while is redundant towards partial or complete failure of a spacecraft. Some of the challenges, associated to the guidance and control aspects of the spacecraft formation, are to maintain a safe separation distance between each spacecraft in the formation to avoid any collision, the distribution of workload between the spacecraft group, and designing fuel efficient trajectories for each spacecraft. This thesis focuses on studying these challenges through two respective mission scenarios, a) the co-location of geostationary satellites, and b) the cooperative visual coverage of an asteroid.The first part of the thesis covers the development of guidance and control strategies to co-locate multiple geostationary satellites safely with a single operational slot. This part of the research is motivated by the growing demand to access the limited Earth resource of geostationary region; the growing use of low-thrust electric propulsion systems for geostationary satellite platforms; and the use of the same propulsion system for station keeping and momentum management of the reaction wheels to maintain a nadir pointing attitude for the satellites. Thus, to address the concurrent maneuver planning problem, a convex-optimization-based algorithm is proposed that incorporates a dual-rate prediction model to address the time scaling difference between the coupled slow orbital and fast attitude dynamics. The use of a combined prediction model in the optimization problem facilitates to include state constraints accounting for the desired orbital and momentum unloading requirements. This algorithm is then extended to the co-location problem, where a leader-follower architecture is adopted to define relative orbital elements of the satellites. The separation distance between the satellites in maintained by defining convex bounds on the relative orbital elements of the follower satellites. The algorithm is then implemented in receding horizon control form to introduce autonomy and to maintain tighter state constraints.The second part covers the trajectory planning for a spacecraft group for the visual coverage mission of an asteroid. In asteroid missions, it is of a specific interest to determine the surface and material properties of the target asteroid by obtaining high-resolution measurements from multiple sites over the asteroid surface. This task can be accomplished using a group of spacecraft, equipped with optical sensors that are moving in proximity to the asteroid. During this mission, an important problem to solve is the to determine a fuel optimal observing sequence and the associated trajectories for a given set of target sites for each spacecraft. However, the completion of the observation task, for a specific site, is limited to the observation time window, usually referred as the period for which a site is illuminated by the Sun. Two trajectory planning algorithms are proposed, which are tested for a single spacecraft case to compare their performance in terms of finding an optimal solution. The travelling salesman based planning algorithm provided near-optimal results in terms of fuel consumption. This algorithm is then extended to the multiple spacecraft case to determine the near-optimal unique observing tour for each spacecraft.The efficacy of the proposed algorithms are evaluated, in terms of fuel consumption and constraints enforcement using several numerical simulations that take into account dominant perturbations in the respective environment.
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| 8. |
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| 9. |
- Satpute, Sumeet G., 1987-, et al.
(författare)
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On Optimal Spacecraft Trajectory Planning for Asteroid Visual Coverage
- 2020
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Ingår i: 2020 28th Mediterranean Conference on Control and Automation (MED). - : IEEE. ; , s. 236-242
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Konferensbidrag (refereegranskat)abstract
- In this article, an optimization based spacecraft trajectory planner for asteroid proximity missions is presented. In asteroid missions, it is of a specific interest to determine the surface and material properties of the target asteroid by obtaining high-resolution measurements from multiple sites over the asteroid surface. During this mission, an important problem to solve is the trajectory planning for the spacecraft, that results into a visual coverage problem for the asteroid surface. However, asteroids provide a challenging target for such missions since they are partially illuminated, rotating, irregular shaped bodies with a low (micro) but irregular gravity field. For addressing this challenging problem, this article will propose a novel optimization approach for the visual coverage of an asteroid. Thus, the proposed trajectory planner's objective is to determine the sequence of the areas to cover and the associated trajectories to achieve this coverage, while considering the motion of the spacecraft, the rotation dynamics of the asteroid, the illumination to each asteroid site and the irregular gravity constraints of the asteroid. The efficacy of the proposed optimal trajectory planner is evaluated through multiple simulation results, where it demonstrates successful optimal coverage of all the desired asteroid areas.
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| 10. |
- Satpute, Sumeet G., 1987-, et al.
(författare)
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Optimization Based Safe and Efficient Trajectory Planning in Proximity of an Asteroid
- 2020
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Ingår i: 2020 7th International Conference on Control, Decision and Information Technologies (CoDIT). - : IEEE. ; , s. 939-945
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Konferensbidrag (refereegranskat)abstract
- This article focuses on a spacecraft trajectory planning algorithm that allows observation of multiple site locations on the asteroid surface, while avoiding any collision with debris objects trapped in the asteroid’s gravity field. Asteroids provide a challenging target for satellite based visual coverage missions, since they are partially illuminated, rotating, irregular shaped celestial bodies with a low but also irregular gravity field. For addressing this problem, an optimization approach for visual coverage is proposed with an objective to determine the sequence of the imaging site locations and the associated safe and fuel efficient trajectories, while considering rotational dynamics of the asteroid, changing illumination condition for each site, irregular gravity constraints of the asteroid and the safe separation distance from the moving debris object. Numerical simulations are performed to demonstrate the ability of the trajectory planner to ensure successful optimal coverage of all the desired asteroid site locations.
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