scholarly journals Design and Optimization of Star Recognition Algorithm Based on Hierarchical CNN

2021 ◽  
Vol 2132 (1) ◽  
pp. 012009
Author(s):  
Wentao Lu ◽  
Gengxin Hua ◽  
Yunfu Zhao ◽  
Jiantao Zhou
Keyword(s):  
Attitude Determination ◽  
Rapid Development ◽  
Recognition Algorithm ◽  
Typical Pattern ◽  
Design And Optimization ◽  
Simulation Performance ◽  
Aerospace Applications ◽  
Star Identification ◽  
Application Fields

Abstract With the rapid-development of AI technology, artificial intelligence algorithms for the aerospace applications have shown very good simulation performance in many areas. Among the spaceborne application fields, star identification can be seen as a typical pattern recognition process. It’s also the key part of attitude determination of the satellites, which requires the algorithm to be robust and efficient due to the limited computing and storing resources of the spaceborne computers. Nevertheless, most of the previous algorithms are not possible to be applied in practical due to the reasons above. This article proposes a strategy of constructing ‘net-structure’ images of stars to build the datasets for training and testing. Besides, a hierarchical convolutional neural network(CNN) with a small size is also designed. It performs good results on robustness and efficiency in the experiments. In the end, a method of fusing the Conv layers and the batch normalization (BN)layers is also adopted to further accelerate the algorithm.

scholarly journals Mobile Networks and Internet of Things Infrastructures to Characterize Smart Human Mobility

Smart Cities ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 894-918
Author(s):  
Luís Rosa ◽  
Fábio Silva ◽  
Cesar Analide
Keyword(s):  
Internet Of Things ◽  
Mobile Networks ◽  
Smart Cities ◽  
Human Mobility ◽  
Rapid Development ◽  
Disruptive Technology ◽  
New Paradigm ◽  
Design And Optimization ◽  
High Level

The evolution of Mobile Networks and Internet of Things (IoT) architectures allows one to rethink the way smart cities infrastructures are designed and managed, and solve a number of problems in terms of human mobility. The territories that adopt the sensoring era can take advantage of this disruptive technology to improve the quality of mobility of their citizens and the rationalization of their resources. However, with this rapid development of smart terminals and infrastructures, as well as the proliferation of diversified applications, even current networks may not be able to completely meet quickly rising human mobility demands. Thus, they are facing many challenges and to cope with these challenges, different standards and projects have been proposed so far. Accordingly, Artificial Intelligence (AI) has been utilized as a new paradigm for the design and optimization of mobile networks with a high level of intelligence. The objective of this work is to identify and discuss the challenges of mobile networks, alongside IoT and AI, to characterize smart human mobility and to discuss some workable solutions to these challenges. Finally, based on this discussion, we propose paths for future smart human mobility researches.

Multi-spacecraft collaborative attitude determination of space tumbling target with experimental verification

2021 ◽  
Vol 185 ◽  
pp. 1-13
Author(s):  
Di Zhao ◽  
Chong Sun ◽  
Zhanxia Zhu ◽  
Wenya Wan ◽  
Zixuan Zheng ◽  
...  
Keyword(s):  
Experimental Verification ◽  
Attitude Determination ◽  
Tumbling Target

scholarly journals Characterization of Degenerate Configurations in Attitude Determination of Three-Vehicle Heterogeneous Formations

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4631
Author(s):  
Pedro Cruz ◽  
Pedro Batista
Keyword(s):  
Unique Solution ◽  
Multiple Solutions ◽  
Attitude Determination ◽  
Line Of Sight ◽  
Number Of Solutions ◽  
Relative Line ◽  
Heterogeneous Formations ◽  
Heterogeneous Formation

The existence of multiple solutions to an attitude determination problem impacts the design of estimation schemes, potentially increasing the errors by a significant value. It is therefore essential to identify such cases in any attitude problem. In this paper, the cases where multiple attitudes satisfy all constraints of a three-vehicle heterogeneous formation are identified. In the formation considered herein, the vehicles measure inertial references and relative line-of-sight vectors. Nonetheless, the line of sight between two elements of the formation is restricted, and these elements are denoted as deputies. The attitude determination problem is characterized relative to the number of solutions associated with each configuration of the formation. There are degenerate and ambiguous configurations that result in infinite or exactly two solutions, respectively. Otherwise, the problem has a unique solution. The degenerate configurations require some collinearity between independent measurements, whereas the ambiguous configurations result from symmetries in the formation measurements. The conditions which define all such configurations are determined in this work. Furthermore, the ambiguous subset of configurations is geometrically interpreted resorting to the planes defined by specific measurements. This subset is also shown to be a zero-measure subset of all possible configurations. Finally, a maneuver is simulated to illustrate and validate the conclusions. As a result of this analysis, it is concluded that, in general, the problem has one attitude solution. Nonetheless, there are configurations with two or infinite solutions, which are identified in this work.

Enzymes and Their Forms Used in Detection of Organophosphorus Compounds

2021 ◽  
pp. 22-41
Keyword(s):  
Organophosphorus Compounds ◽  
Degradation Products ◽  
Rapid Development ◽  
Hydrolytic Enzymes ◽  
Immobilized Enzymes ◽  
Amino Acid Sequences ◽  
Practical Implementation ◽  
Scientific Results ◽  
Physical And Chemical

Еnzymes are able to effectively interact with various organophosphorus compounds (OPC), entering into (bio)chemical reactions with them. Changes in the initial activity of enzymes as a result of their inhibition by OPC, the formation of OPC degradation products under the action of hydrolytic enzymes, etc. can be determined using different physical and chemical methods and used in bioanalytic systems to determine the concentrations of OPC. The purpose of the review is to analyze the main scientific results achieved over the past 10 years in the development of analytical systems based on enzymes intended for the determination of OPC. It is shown in the article, that the requirements for the sensitivity of biosensors are based on the norms of the content of the analyzed substances detected in/at the objects of mandatory control. The cholinesterases compose a basis for the development of the largest number of ultra-sensitive biosensors, although other enzymes can be successfully used as a biosensitive element. The most technologically advanced solution that is close to the practical implementation seems to be bioanalytical systems using immobilized enzymes. Improving the detection limits of the OPC can be achieved by using nanoobjects together with modern methods of signal transducers, for example, with nanomechanical detectors and signal converters. This combination of technical solutions ensures the sensitivity of the OPC analysis up to pg/l. At present, «reagentless» systems have received significant development, which have become the basis for the production of a large number of commercially available strips for the express determination of OPC. Modern demands stimulate the rapid development of portable and, especially, wearable biosensors that can be attached to various surfaces, including a clothing. The progress in the development of affine amino acid sequences, in the future, will allow the creation of enzyme biosensors on any surface.

scholarly journals A General Fitting Function to Estimate Apparent Reaction Orders of Kinetic Profiles

2019 ◽  
Author(s):  
Robert Pollice
Keyword(s):  
Chemical Reactions ◽  
Catalyst Deactivation ◽  
Rapid Development ◽  
Product Inhibition ◽  
Time Profile ◽  
Time Data ◽  
Concentration Time ◽  
Wide Range ◽  
Reaction Orders

The rapid development of analytical methods in recent decades has resulted in a wide range of readily available and accurate reaction-monitoring techniques, which allow for easy determination of high-quality concentration-time data of chemical reactions. However, while the acquisition of kinetic data has become routine in the development of new chemical reactions and the study of their mechanisms, not all the information contained therein is utilized because of a lack of suitable analysis tools which unnecessarily complicates mechanistic studies. Herein, we report on a general method to analyze a single concentration-time profile of chemical reactions and extract information regarding the reaction order with respect to substrates, the presence of multiple kinetic regimes, and the presence of kinetic complexities, such as catalyst deactivation, product inhibition, and substrate decomposition.<br>

scholarly journals Bibliometrics and visualization analysis of China's Service Quality Development Trend

2021 ◽  
Vol 233 ◽  
pp. 01164
Author(s):  
Lei Xu ◽  
Yuan Ni ◽  
Pengfei Han ◽  
Teng Zhang
Keyword(s):  
Social Network ◽  
Service Quality ◽  
Visual Analysis ◽  
Rapid Development ◽  
Development Trend ◽  
Network Evolution ◽  
Data Source ◽  
Application Fields ◽  
High Level ◽  
The Development Trend

From the aspect of bibliometrics and social network analysis, this paper studies the content characteristics and network evolution of service quality in China, form visual analysis charts and summarizes the research hotspots and development trends. Taking CNKI database as the data source, data mining and association analysis of sample data were carried out by means of manual judgment, keyword co-occurrence, bibliometric software BICOMB and Pajek. 872 related literatures were retrieved from 1999 to 2019, and the tendency of the number of published papers in each year was close to the inverted U type. This study expands the application fields of bibliometrics and social network software, and analyzes the development trend of service quality. The theoretical and practical research on service quality has achieved rapid development in the past 20 years. The library service quality and service quality satisfaction have always gotten a high level of attention, and the characteristics of network platforms for service quality have gradually become apparent because of the development of the Internet and computer technology.

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