scholarly journals Vision-Based Approaches of the Small Satellites Relative Navigation

2021 ◽  
Vol 9 ◽  
pp. 13-20
Author(s):  
Tuncay Yunus Erkec ◽  
Chingiz Hajiyev
Keyword(s):  
Relative Position ◽  
Point Of View ◽  
Relative Navigation ◽  
Small Satellites ◽  
Navigation Control ◽  
Navigation Strategies

This paper means to comprehend vision-based relative navigation strategies which are utilized forsmall/micro satellites. Advancements dependent on this technique are utilized separately or joined with oneanother to deal with relative position issues. The benefits and detriments of vision-based relative navigationmodels change as indicated by space of utilization and stage type. Various strategies and approaches exist andneed distinctive assessment and advanced algorithms for variation, control, and sensor combination. Each ofthe models centering inside expects those ideal disposition conditions. This paper just spotlights on relativeroute and distance point of view. Additionally, the point of this article is to comprehend the connectionbetween's general navigation control frameworks and the adequacy of calculation, which are utilized inassessing the states during gathering or development flight/development.

scholarly journals The position of the farm holiday in Austrian tourism

2019 ◽  
Vol 4 (1) ◽  
pp. 697-711 ◽  
Author(s):  
Erika Quendler
Keyword(s):  
Empirical Research ◽  
Relative Position ◽  
Secondary Data ◽  
Point Of View ◽  
Local Context ◽  
Supply Side ◽  
Data Sets ◽  
Demand Side ◽  
Tourist Destinations ◽  
Tourist Accommodation

AbstractTourism is vitally important to the Austrian economy. The number of tourist destinations, both farms and other forms of accommodation, in the different regions of Austria is considerably and constantly changing. This paper discusses the position of the ‘farm holiday’ compared to other forms of tourism. Understanding the resilience of farm holidays is especially important but empirical research on this matter remains limited. The term ‘farm holiday’ covers staying overnight on a farm that is actively engaged in agriculture and has a maximum of 10 guest beds. The results reported in this paper are based on an analysis of secondary data from 2000 and 2018 by looking at two types of indicator: (i) accommodation capacity (supply side) and (ii) attractiveness of a destination (demand side). The data sets cover Austria and its NUTS3 regions. The results show the evolution of farm holidays vis-à-vis other forms of tourist accommodation. In the form of a quadrant matrix they also show the relative position of farm holidays regionally. While putting into question the resilience of farm holidays, the data also reveals where farm holidays could act to expand this niche or learn and improve to effect a shift in their respective position relative to the market ‘leaders’. However, there is clearly a need to learn more about farm holidays within the local context. This paper contributes to our knowledge of farm holidays from a regional point of view and tries to elaborate on the need for further research.

Relative navigation control of articulated vehicle based on LTV-MPC

2021 ◽  
Vol 28 (1) ◽  
pp. 34
Author(s):  
Li Liu ◽  
Yu Meng ◽  
Weidong Luo ◽  
Qing Gu ◽  
Guoxing Bai
Keyword(s):  
Relative Navigation ◽  
Articulated Vehicle ◽  
Navigation Control

scholarly journals Optimization of Tubular Microalgal Photobioreactors with Spiral Ribs under Single-Sided and Double-Sided Illuminations

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 619 ◽  
Author(s):  
Lei ◽  
Wang ◽  
Wu
Keyword(s):  
Relative Position ◽  
High Efficiency ◽  
Raw Materials ◽  
Incident Light ◽  
Clean Energy ◽  
Point Of View ◽  
Utilization Efficiency ◽  
Cycle Frequency ◽  
Algal Suspension ◽  
Rib Structure

Microalgae can be raw materials for the production of clean energy and have great potential for development. The design of the microalgal photobioreactor (PBR) affects the mixing of the algal suspension and the utilization efficiency of the light energy, thereby affecting the high-efficiency cultivation of the microalgae. In this study, a spiral rib structure was introduced into a tubular microalgal PBR to improve the mixing performance and the light utilization efficiency. The number of spiral ribs, the inclination angle, and the velocity of the algal suspension were optimized for single-sided and double-sided parallel light illuminations with the same total incident light intensity. Next, the optimization results under the two illumination modes were compared. The results showed that the double-sided illumination did not increase the average light/dark (L/D) cycle frequency of the microalgae particles, but it reduced the efficiency of the L/D cycle enhancement. This outcome was analyzed from the point of view of the relative position between the L/D boundary and the vortex in the flow field. Finally, a method to increase the average L/D cycle frequency was proposed and validated. In this method, the relative position between the L/D boundary and the vortex was adjusted so that the L/D boundary passed through the central region of the vortex. This method can also be applied to the design of other types of PBRs to increase the average L/D cycle frequency.

scholarly journals Deserted Medieval Village Reconstruction Using Applied Geosciences

2020 ◽  
Vol 12 (12) ◽  
pp. 1975
Author(s):  
Alexandru Hegyi ◽  
Apostolos Sarris ◽  
Florin Curta ◽  
Cristian Floca ◽  
Sorin Forțiu ◽  
...  
Keyword(s):  
High Resolution ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Vegetation Indices ◽  
Archaeological Site ◽  
Point Of View ◽  
Surface Model ◽  
Small Satellites ◽  
High Resolution Images ◽  
Remote Sensing Techniques

This study presents a new way to reconstruct the extent of medieval archaeological sites by using approaches from the field of geoinformatics. Hence, we propose a combined use of non-invasive methodologies which are used for the first time to study a medieval village in Romania. The focus here will be on ground-based and satellite remote-sensing techniques. The method relies on computing vegetation indices (proxies), which have been utilized for archaeological site detection in order to detect the layout of a deserted medieval town located in southwestern Romania. The data were produced by a group of small satellites (3U CubeSats) dispatched by Planet Labs which delivered high-resolution images of the Earth’s surface. The globe is encompassed by more than 150 satellites (dimensions: 10 × 10 × 30 cm) which catch different images for the same area at moderately short intervals at a spatial resolution of 3–4 m. The four-band Planet Scope satellite images were employed to calculate a number of vegetation indices such as NDVI (Normalized Difference Vegetation Index), DVI (Difference Vegetation Index), SR (Simple Vegetation Ratio) and others. For better precision, structure from motion (SfM) techniques were applied to generate a high-resolution orthomosaic and a digital surface model in which the boundaries of the medieval village of “Șanțul Turcilor” in Mașloc, Romania, can be plainly observed. Additionally, this study contrasts the outcomes with a geophysical survey that was attempted inside the central part of the medieval settlement. The technical results of this study also provide strong evidence from an historical point of view: the first documented case of village systematization during the medieval period within Eastern Europe (particularly Romania) found through geoscientific methods.

Cortinarius lentus (Agaricales, Cortinariaceae), a new species in section Calochroi

Phytotaxa ◽  
2020 ◽  
Vol 447 (1) ◽  
pp. 31-41
Author(s):  
FRANCESCO DOVANA ◽  
FABRIZIO BOCCARDO ◽  
MARCO CLERICUZIO ◽  
ALFREDO VIZZINI
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Relative Position ◽  
Habitat Preference ◽  
Point Of View ◽  
Pale Yellow ◽  
Its Regions ◽  
Genetic Features ◽  
Yellow Orange ◽  
A New Species

A new species of Cortinarius sect. Calochroi, C. lentus, is described on the basis of morphological and genetic features. It is characterised by a yellow-orange to brown-orange pileus, initially violaceous pink lamellae, a cream to pale yellow universal veil, amygdaliform to almost citriform spores, coarsely verrucose, typically narrow (Qav = 1.9) and habitat preference for chestnut woods on acidophilic soil. It is compared with the closest species from a morphological point of view, in particular with C. leochrous and C. calochrous. In order to assess its relative position within Calochroi, a phylogenetic approach based on RPB1 and ITS regions was performed. The ITS phylogenetic analysis did not resolve the position of C. lentus within sect Calochroi, but in our RPB1 phylogenetic analysis, C. sublilacinopes is closely related.

Development of a Generic Guidance Navigation & Control System for Small Satellites: Application to HuskySat-1

2018 ◽  
Author(s):  
Taylor Reynolds ◽  
Krish Kaycee ◽  
Bijan Barzgaran ◽  
Mathias Hudoba de Badyn ◽  
Sean Rice ◽  
...  
Keyword(s):  
Control System ◽  
Small Satellites ◽  
Navigation Control

Correction: Development of a Generic Guidance Navigation & Control System for Small Satellites: Application to HuskySat-1

2018 ◽  
Author(s):  
Taylor Reynolds ◽  
Krish Kaycee ◽  
Bijan Barzgaran ◽  
Mathias Hudoba de Badyn ◽  
Sean Rice ◽  
...  
Keyword(s):  
Control System ◽  
Small Satellites ◽  
Navigation Control

scholarly journals A Novel Relative Navigation Control Strategy Based on Relation Space Method for Autonomous Underground Articulated Vehicles

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Fengqian Dou ◽  
Yu Meng ◽  
Li Liu ◽  
Qing Gu
Keyword(s):  
Neural Network ◽  
Control Strategy ◽  
Speed Control ◽  
Relative Navigation ◽  
Competitive Neural Network ◽  
Articulated Vehicles ◽  
Navigation Control ◽  
Control Modules ◽  
Optimal Driving ◽  
Space Method

This paper proposes a novel relative navigation control strategy based on the relation space method (RSM) for articulated underground trackless vehicles. In the RSM, a self-organizing, competitive neural network is used to identify the space around the vehicle, and the spatial geometric relationships of the identified space are used to determine the vehicle’s optimal driving direction. For driving control, the trajectories of the articulated vehicles are analyzed, and data-based steering and speed control modules are developed to reduce modeling complexity. Simulation shows that the proposed RSM can choose the correct directions for articulated vehicles in different tunnels. The effectiveness and feasibility of the resulting novel relative navigation control strategy are validated through experiments.

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