scholarly journals Quaternion versus Rotation Matrix Feedback for Spacecraft Attitude Stabilization Using Magnetorquers

Aerospace ◽  
2022 ◽  
Vol 9 (1) ◽  
pp. 24
Author(s):  
Fabio Celani
Keyword(s):  
Monte Carlo ◽  
Rotation Matrix ◽  
Point Of View ◽  
Spacecraft Attitude ◽  
Speed Of Convergence ◽  
Attitude Stabilization ◽  
Mathematical Point ◽  
Rate Feedback ◽  
Numerical Case Study

The purpose of this paper is to compare performances between stabilization algorithms of quaternion plus attitude rate feedback and rotation matrix plus attitude rate feedback for an Earth-pointing spacecraft with magnetorquers as the only torque actuators. From a mathematical point of view, an important difference between the two stabilizing laws is that only quaternion feedback can exhibit an undesired behavior known as the unwinding phenomenon. A numerical case study is considered, and two Monte Carlo campaigns are carried out: one in nominal conditions and one in perturbed conditions. It turns out that quaternion feedback compares more favorably in terms of the speed of convergence in both campaigns, and it requires less energy in perturbed conditions.

scholarly journals Stochastic operation of isolated microgrids: aggregating-rule-based optimization versus standard approaches

2021 ◽  
Vol 238 ◽  
pp. 02005
Author(s):  
Davide Fioriti ◽  
Giovanni Lutzemberger ◽  
Davide Poli ◽  
Pablo Duenas-Martinez
Keyword(s):  
Monte Carlo ◽  
Power Systems ◽  
Stochastic Approach ◽  
Operating Costs ◽  
Energy Sources ◽  
Rule Based ◽  
Small Power ◽  
Forecasting Errors ◽  
Numerical Case Study

Stochastic operation of power systems has risen attention of researchers as fluctuating energy sources like renewables are being increasingly integrated into existing grids. Uncertainties can be higher in small power systems like isolated microgrids, where both renewables and load can be extremely unpredictable, thus causing increasing operating costs and business risks. In the last years, many approaches have been proposed to account for uncertainties in off-grid microgrids, usually simulating several size, load and renewables scenarios. Among them, a simplified stochastic approach, namely Aggregating-Rule-based Stochastic Optimization (ARSO), which decomposes the N-scenario problem into N deterministic subproblems whose solutions are finally processed and aggregated, has been recently proposed with interesting results in terms of optimality of results and computational requirements. In this paper, two ARSO approaches are compared with standard stochastic and deterministic methodologies used to operate isolated microgrids, to assess advantages and drawbacks of all these techniques and their ability in handling uncertainties. The two ARSO methodologies differ in the aggregating rule: to take into account the load and RES forecasting errors, the Improved-ARSO employs a Monte Carlo procedure, whereas the Mixed ARSO technique makes use of statistical rules. A numerical case study for a typical isolated microgrid in Africa is proposed and discussed.

An Integrated Tourism Model based on Local Identity for Ecological, Historical, and Cultural Tourism

2018 ◽  
Vol 3 (7) ◽  
Author(s):  
Natapon Anusorntharangkul ◽  
Yanin Rugwongwan
Keyword(s):  
Environmental Design ◽  
Cultural Tourism ◽  
Marketing Strategies ◽  
Point Of View ◽  
Local Identity ◽  
Design Elements ◽  
Resources Management ◽  
The North ◽  
North Eastern

The objective of this paper is to study local identity and explore the potential for regional resources management and valuation of the historic environment a case study of the north-eastern provinces of Thailand, for guiding the tourism environmental design elements. The point of view has the goal creative integrate tourism model and product development from local identity embedded localism. This concept advocates the philosophy that tourism businesses must develop products and marketing strategies that not only address the needs of consumers but also safeguard the local identity. 

Design process for serious activities inspired by play and games: a problem solving with a board game from disengamement and gamification processes (Preprint)

2020 ◽  
Author(s):  
Stéphane Goria ◽  
Louise Dupet ◽  
Maëva Négroni ◽  
Gabriel Sega ◽  
Philippe Arnoux ◽  
...  
Keyword(s):  
Cancer Detection ◽  
Serious Games ◽  
Diagnostic Method ◽  
Scientific Literature ◽  
Imaging Techniques ◽  
Point Of View ◽  
Board Game ◽  
Advantages And Disadvantages ◽  
Design Result

BACKGROUND most serious games and other game-based tools are designed as digital games or escape games. They are designed for learning or sometimes in the field of medicine as an aid to care. However, they can also be seen as an aid to research, in our case, to evaluate the advantages and disadvantages of imaging techniques for cancer detection. OBJECTIVE we present a case study of action research on the design of a serious board game intended to consider the advantages and weaknesses of a diagnostic method in a different ways. The goal was to better understand the principles of designing a tool using game or play. METHODS we explicitly implemented another process than gamification to develop a structure reminiscent of the game to highlight the strengths and weaknesses of different imaging techniques from the point of view of the respondents (in this case specialists not directly involved in the project). Based on this feedback and the scientific literature on this subject, we detail the main categories of games and games developed for serious use in order to understand their differences. Concerning the cancer research part to which game contributes, our method is based on questions asked to experts and practitioners of this specialty. RESULTS an expert point of view translation tool in the form of a game has been realized to apprehend a research in a different way. CONCLUSIONS we show with the help of a diagram, some possible design paths leading to this type of design result including two hidden dimensions to consider (the awareness of the game or play by the "player" and his role as a contributor or recipient).

Bleak Weather for Sun-Shine AG: A Case Study of Impairment of Assets

2014 ◽  
Vol 30 (2) ◽  
pp. 113-126 ◽  
Author(s):  
Dominic Detzen ◽  
Tobias Stork genannt Wersborg ◽  
Henning Zülch
Keyword(s):  
Real Life ◽  
Accounting Standards ◽  
Point Of View ◽  
Professional Judgment ◽  
Economic Point ◽  
Instructional Resource

ABSTRACT This case originates from a real-life business situation and illustrates the application of impairment tests in accordance with IFRS and U.S. GAAP. In the first part of the case study, students examine conceptual questions of impairment tests under IFRS and U.S. GAAP with respect to applicable accounting standards, definitions, value concepts, and frequency of application. In addition, the case encourages students to discuss the impairment regime from an economic point of view. The second part of the instructional resource continues to provide instructors with the flexibility of applying U.S. GAAP and/or IFRS when students are asked to test a long-lived asset for impairment and, if necessary, allocate any potential impairment. This latter part demonstrates that impairment tests require professional judgment that students are to exercise in the case.

scholarly journals The “Zero Miles Product” Concept Applied to Biofuel Production: A Case Study

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 565
Author(s):  
Nikolaj Kaae Kirk ◽  
Clara Navarrete ◽  
Jakob Ellegaard Juhl ◽  
José Luis Martínez ◽  
Alessandra Procentese
Keyword(s):  
Sugar Content ◽  
Point Of View ◽  
Biofuel Production ◽  
Transport Costs ◽  
Economic Point ◽  
Product Concept ◽  
Energy Demands ◽  
Production Platform ◽  
High Sugar Content

To make biofuel production feasible from an economic point of view, several studies have investigated the main associated bottlenecks of the whole production process through approaches such as the “cradle to grave” approach or the Life Cycle Assessment (LCA) analysis, being the main constrains the feedstock collection and transport. Whilst several feedstocks are interesting because of their high sugar content, very few of them are available all year around and moreover do not require high transportation’ costs. This work aims to investigate if the “zero miles” concept could bring advantages to biofuel production by decreasing all the associated transport costs on a locally established production platform. In particular, a specific case study applied to the Technical University of Denmark (DTU) campus is used as example to investigate the advantages and feasibility of using the spent coffee grounds generated at the main cafeteria for the production of bioethanol on site, which can be subsequently used to (partially) cover the campus’ energy demands.

scholarly journals Comparison of Direct and Adjoint k and α-Eigenfunctions

2021 ◽  
Vol 2 (2) ◽  
pp. 132-151
Author(s):  
Vito Vitali ◽  
Florent Chevallier ◽  
Alexis Jinaphanh ◽  
Andrea Zoia ◽  
Patrick Blaise
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Methods ◽  
Energy Transport ◽  
Distinct Point ◽  
Point Of View ◽  
Critical Systems ◽  
Small Deviations ◽  
Power Iteration ◽  
Continuous Energy ◽  
Fission Probability

Modal expansions based on k-eigenvalues and α-eigenvalues are commonly used in order to investigate the reactor behaviour, each with a distinct point of view: the former is related to fission generations, whereas the latter is related to time. Well-known Monte Carlo methods exist to compute the direct k or α fundamental eigenmodes, based on variants of the power iteration. The possibility of computing adjoint eigenfunctions in continuous-energy transport has been recently implemented and tested in the development version of TRIPOLI-4®, using a modified version of the Iterated Fission Probability (IFP) method for the adjoint α calculation. In this work we present a preliminary comparison of direct and adjoint k and α eigenmodes by Monte Carlo methods, for small deviations from criticality. When the reactor is exactly critical, i.e., for k0 = 1 or equivalently α0 = 0, the fundamental modes of both eigenfunction bases coincide, as expected on physical grounds. However, for non-critical systems the fundamental k and α eigenmodes show significant discrepancies.

Where is semiotic-cultural constructivism in psychology heading? Contemporary reflections on the trajectory of an approach to cultural psychology

2021 ◽  
pp. 1354067X2110173
Author(s):  
Danilo Silva Guimarães
Keyword(s):  
Knowledge Construction ◽  
Cultural Psychology ◽  
Scientific Progress ◽  
Human Action ◽  
Point Of View ◽  
Cultural Experience ◽  
Ethical Implications ◽  
Psychological Knowledge ◽  
The Relationship

This article aims to discuss the relationship between personal cultural experience and knowledge construction in psychology, from the perspective of the Semiotic-Cultural Constructivism. The thoughts here presented are, at the same time, from within psychology and about psychology. The researcher is culturally situated and science is a field of production of cultural works that aims to create perspectives of knowledge about the world. Researchers can and must create some detachment from their field of study to be able to understand the course of their own knowledge constructions. This detachment is achieved through a historical–philosophical view on the theoretical–methodological propositions of their field of research. As a case study, we selected for analysis the field’s pioneer productions, from the years 1982 to 2004. The material showed that the rationality that characterizes scientific research is directed, in this field, to creating semiotic resources for further developing reflexivity in psychology, as a recursive and open-ended process. The theoretical–methodological work of the researcher concerns its own personal cultural experience and the tradition of the already constructed knowledge, selected to a dialogue about the ethical implications of human action. Therefore, advances in psychological knowledge construction cannot be addressed from an external, allegedly neutral point of view, focused on the efficacy of the instruments resulting from the said “scientific progress.”

scholarly journals Enhancing Maritime Crew Resource Management Training by Applying Resilience Engineering: A Case Study of the Bachelor Maritime Officer Training Programme in Rotterdam

2021 ◽  
Vol 11 (8) ◽  
pp. 378
Author(s):  
Jaco Griffioen ◽  
Monique van der Drift ◽  
Hans van den Broek
Keyword(s):  
Resource Management ◽  
Human Error ◽  
Crew Resource Management ◽  
Management Training ◽  
Training Programme ◽  
Point Of View ◽  
Safety Performance ◽  
Resilience Engineering ◽  
Crew Resource Management Training

This paper sets out to enhance current Maritime Crew Resource Management (MCRM) training, and with that to improve the training of technical and non-technical skills given to bachelor maritime officers. The rationale for CRM training is improving safety performance by reducing accidents caused by human error. The central notion of CRM training is that applying good resource management principles during day-to-day operations will lead to a beneficial change in attitudes and behaviour regarding safety. This article therefore indicates that enhanced MCRM should play a more structural role in the training of student officers. However, the key question is: what are the required changes in attitude and behaviour that will create sufficient adaptability to improve safety performance? To provide an answer, we introduce the Resilience Engineering (RE) theory. From an RE point of view, we elaborate on the relation between team adaptability and safety performance, operationalized as a competence profile. In addition, a case study of the ‘Rotterdam Approach’ will be presented, in which the MCRM training design has been enhanced with RE, with the objective to train team adaptability skills for improved safety performance.

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