scholarly journals A Mobility Determination Method for Parallel Platforms Based on the Lie Algebra of SE(3) and Its Subspaces

2021 ◽  
pp. 1-12
Author(s):  
Alejandro de Jesús Sánchez-García ◽  
José M. Rico ◽  
J. Jesús Cervantes-Sánchez ◽  
Pablo Lopez-Custodio
Keyword(s):  
Lie Algebra ◽  
Screw Theory ◽  
Determination Method ◽  
Mobility Analysis ◽  
Euclidean Group ◽  
Second Stage ◽  
Direct Sum ◽  
Three Stages ◽  
Last Stage ◽  
Special Euclidean Group

Abstract This contribution presents a screw theory-based method for determining the mobility of fully parallel platforms. The method is based in the application of three stages. The first stage involves the application of the intersection of the subalgebras of Lie algebra, se(3), of the special Euclidean group, SE(3), associated with the legs of the platform. The second stage analyzes the possibility of the legs of the platform generating a sum or direct sum of two subalgebras of the Lie algebra, se(3). The last stage, if necessary, considers the possibility of the kinematic pairs of the legs satisfying certain velocity conditions; these conditions allow to reduce the platform's mobility analysis to one that can solved using one of the two previous stages.

scholarly journals A Mobility Determination Method for Parallel Platforms Based on the Lie Algebra of SE(3) and its Subspaces

2020 ◽  
Author(s):  
A. J. Sánchez-García ◽  
J. M. Rico ◽  
J. J. Cervantes-Sánchez ◽  
P. C. López-Custodio
Keyword(s):  
Lie Algebra ◽  
Screw Theory ◽  
Determination Method ◽  
Mobility Analysis ◽  
Euclidean Group ◽  
Second Stage ◽  
Direct Sum ◽  
Three Stages ◽  
Last Stage ◽  
Special Euclidean Group

Abstract This contribution presents a screw theory-based method for determining the mobility of fully parallel platforms. The method is based in the application of three stages. The first stage involves the application of the intersection of the subalgebras of Lie algebra, se(3), of the special Euclidean group, SE(3), associated with the legs of the platform. The second stage analyzes the possibility of the legs of the platform generating a sum or direct sum of two subalgebras of the Lie algebra, se(3). The last stage, if necessary, considers the possibility of the kinematic pairs of the legs satisfying certain velocity conditions; these conditions allow to reduce the platform’s mobility analysis to one that can solved using one of the two previous stages.

scholarly journals The Design Process at Le Corbusier, Case of the Ronchamp Chapel

2019 ◽  
Vol 1 (1) ◽  
pp. 1275-1282
Author(s):  
Nadjat Outmoune ◽  
Abdelmalek Arrouf
Keyword(s):  
Empirical Studies ◽  
Data Gathering ◽  
Le Corbusier ◽  
Generic Model ◽  
Design Activity ◽  
Genetic Method ◽  
Second Stage ◽  
Three Stages ◽  
Last Stage

AbstractThis work falls within the empirical studies of design activity. Its project is to understand Le Corbusier's designing way and how does he work and structure his design processes. Doing so, it jumps above the descriptive and doctrinal knowledge of objects produced by “Le Corbusier” to study the actions and mechanisms that led to them.To achieve its aim, this study uses genetic method, developed by P.M. De Biasi of literary origin, this research method is made of three stages. The first one, which is of empirical nature, is one of data gathering. It leads to the establishment of genesis tables and to the classification of the all collected documents. The second stage, makes the analysis of all the collected documents one by one. It allows the restitution of the creative process of one projects “Le Corbusier” which is “la chapelle de Notre Dame du haut de Ronchamp”. The last stage is finally that define the design processe of the this project. The results show that the design activity of “Le Corbuiser” obeys the overall logic of one generic model which may be called his individual designing style.

Materials Flow Analysis in the Production Process - Case Study

2014 ◽  
Vol 474 ◽  
pp. 97-102 ◽  
Author(s):  
Grzegorz Królczyk ◽  
Stanisław Legutko ◽  
Jolanta Królczyk ◽  
Ewelina Tama
Keyword(s):  
Production Process ◽  
Machine Tools ◽  
Flow Analysis ◽  
Spatial Location ◽  
Second Stage ◽  
Three Stages ◽  
Last Stage ◽  
Internal Transport ◽  
Materials Flow

The paper presents an analysis of the materials flow in the company on the example of the production process of the selected product. The analysis was carried out in three stages. This division has enabled to take into account many factors that have a significant impact on the internal transport during production. The first step in the analysis was to determine the current situation of the flow of materials. In the second stage, the obtained data were used to develop a detailed program of internal transport, associated with the production of the considered product, and the last stage of the analysis was to identify opportunities for rationalization actions. The rationalization concerned the machine tools spatial location, the choice of handling equipment and transport tasks.

Spelling reformers and artificial language advocates

2017 ◽  
Vol 41 (3) ◽  
pp. 287-303
Author(s):  
Roberto Garvía
Keyword(s):  
The United States ◽  
Political Environment ◽  
Artificial Language ◽  
Second Stage ◽  
The United Kingdom ◽  
The Status ◽  
International Standing ◽  
Three Stages ◽  
Last Stage ◽  
Neutral Language

Abstract This article explores the shifting relations that took place from the last decades of the 19th to the first years of the 20th century between two of the most innovative language movements of the time: the spelling reform and the artificial language movements. The article focuses on the United States, the United Kingdom, Germany and France. Although both movements shared a similar language ideology which run counter to the organicist perception of language and emphasized its democratic function, the article shows how the shifting political environment in which they operated affected their relation. The article identifies three stages. In a first stage, and convinced that the reform of the spelling and the promotion of an artificial, neutral language were not mutually exclusive projects, the spelling reformers were favorably inclined towards artificial language projects. In a second stage relations began to skew when some reformers advocated for the “natural Esperanto” solution, which implied the promotion of a small language to the status of the international lingua franca. In the last stage, when nationalist sentiments and international rivalries mounted, the spelling reformers broke ties with the artificial language movement and worked to improve as much as possible the international standing of their own languages.

scholarly journals A Novel Approach for Detection of Fake News on Social Media Using Metaheuristic Optimization Algorithms

2019 ◽  
Vol 25 (4) ◽  
pp. 62-67 ◽  
Author(s):  
Feyza Altunbey Ozbay ◽  
Bilal Alatas
Keyword(s):  
Artificial Intelligence ◽  
Social Media ◽  
Fake News ◽  
Second Stage ◽  
Novel Approach ◽  
Three Stages ◽  
Last Stage ◽  
Real World Datasets ◽  
First Time ◽  
Metaheuristic Optimization Algorithms

Deceptive content is becoming increasingly dangerous, such as fake news created by social media users. Individuals and society have been affected negatively by the spread of low-quality news on social media. The fake and real news needs to be detected to eliminate the disadvantages of social media. This paper proposes a novel approach for fake news detection (FND) problem on social media. Applying this approach, FND problem has been considered as an optimization problem for the first time and two metaheuristic algorithms, the Grey Wolf Optimization (GWO) and Salp Swarm Optimization (SSO) have been adapted to the FND problem for the first time as well. The proposed FND approach consists of three stages. The first stage is data preprocessing. The second stage is adapting GWO and SSO for construction of a novel FND model. The last stage consists of using proposed FND model for testing. The proposed approach has been evaluated using three different real-world datasets. The results have been compared with seven supervised artificial intelligence algorithms. The results show GWO algorithm has the best performance in comparison with SSO algorithm and the other artificial intelligence algorithms. GWO seems to be efficiently used for solving different types of social media problems.

scholarly journals The Stages of Student Mathematical Imagination in Solving Mathematical Problems

2017 ◽  
Vol 10 (7) ◽  
pp. 48 ◽  
Author(s):  
Teguh Wibowo ◽  
Akbar Sutawidjaja ◽  
Abdur Rahman As’ari ◽  
I Made Sulandra
Keyword(s):  
Qualitative Study ◽  
Research Subjects ◽  
Second Stage ◽  
Mathematical Problems ◽  
Three Stages ◽  
Last Stage

This research is a qualitative study that aimed to describe the stages of students mathematical imagination in solving mathematical problems. There are three kinds of mathematical imagination in solving mathematical problems, namely sensory mathematical imagination, creative mathematical imagination and recreative mathematical imagination. Students can produce one kind of mathematical imagination or other kinds of mathematical imagination. Problem sheet is used as a supporting instrument to find out the stages of students mathematical imagination in solving problems. Three students are used as research subjects in whom students were able to produce their mathematical imagination in solving mathematical problems. The results showed that there are three stages of students mathematical imagination in solving mathematical problems, the first stage is sensory mathematical imagination, the second stage is creative mathematical imagination, and the last stage is recreative mathematical imagination.

scholarly journals Desa Mitra dalam Budidaya Tanaman Obat Keluarga Menuju Desa Cibiru Wetan sebagai Sentra Herbal

2018 ◽  
Vol 3 (2) ◽  
pp. 159-164
Author(s):  
Fauzan Zein Muttaqin ◽  
Widhya Aligita ◽  
Soni Muhsinin ◽  
Dadang Juanda ◽  
Aiyi Asnawi
Keyword(s):  
Medicinal Plants ◽  
Women Farmers ◽  
Second Stage ◽  
Plant Cultivation ◽  
Participation Of Women ◽  
Third Stage ◽  
Effective Technology ◽  
Three Stages ◽  
Last Stage ◽  
Farmer Groups

PARTNER VILLAGE IN FAMILY MEDICINE PLANT CULTIVATION TOWARDS CIBIRU WETAN VILLAGE AS A HERBAL CENTER. The area of ​​Cibiru Wetan Village is a farming area because besides the limited water supply, the land is hilly. With the initiative and participation of women farmer groups which had so many achievements and skills, it was necessary to explore the potential that could provide a new icon for Cibiru Wetan Village. The purpose of the activity was to socialize and practice the cultivating of the medicinal plants carried out by a group of women farmers with simple and effective technology and finally able to become a center of dried herbs production. The method used in the cultivation program for medicinal plants was divided into three stages. The first stage was to provide material counseling on family medicinal plants including the understanding of the benefits of the plant, the second stage was to provide an explanation or training in planting family medicinal plants and the last stage or third stage was to practice directly in planting these medicinal plants. The results showed a positive understanding of both groups for both the socialization and counseling stages as well as for the practice of medicinal plants cultivation. It could be concluded, the partner village activities in medicinal plants cultivation could improve the understanding of the target group.

scholarly journals Russia, the 1990s: Metamorphoses of the Emerging Polity

2021 ◽  
Vol 102 (3) ◽  
pp. 72-98
Author(s):  
L. E. Bliakher
Keyword(s):  
The Political ◽  
Chaotic State ◽  
Legal Norms ◽  
Second Stage ◽  
Political Center ◽  
Regional Community ◽  
Three Stages ◽  
Last Stage ◽  
State Of Affairs ◽  
Federal Center

The article attempts to examine the era of the 1990s through the prism of communication in the system “center — regions”. The author interprets the epoch itself as a special, chaotic state of affairs. The political structures and instruments inherited by the new Russia from the Soviet times did not disappear, but lost their foundation (which corresponded to the model of Russian power described by Yuri Pivovarov), transformed into the mode of an autonomous drift along unauthorized trajectories. The new foundation (“the path of civilized countries”) came into conflict with the structures and instruments themselves. The situation was exacerbated by the fact that the rejection of that foundation deprived the political center of its legitimacy, since it was perceived and legitimized as a driver of the transition from socialism into the world of “civilized countries”. The article shows that it was the space of dialogue (bargaining) between the center and the regions that combined the principles of the Russian power and a new legitimizing foundation stemming from the “civilized countries” The author identifies three stages of such a dialogue. During the first stage, there was no adaptation, and the dialogue ended with a violent confrontation. As a result, two parallel realities emerged — the reality of legal norms and declarations and the reality of survival. The second stage, labeled by the author as “taming Europe”, witnessed democratic procedures uniting with the practices of the Russian power and recreation of the distributive economy at the regional level. At the same time, the dual legitimacy of the regional rulers — from the regional community and from the federal center — bound the country’s territory much stronger than enforcement agencies or future “spiritual staples”. The last stage, which is usually considered to take place after the 1990s, is associated with the transfer of practices that have developed in the regions to the center. However, according to the author’s conclusion, this is not the end of the constituent era and the formation of the polity, but a continuation of the quest.

scholarly journals A Portable Elbow Exoskeleton for Three Stages of Rehabilitation

2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Soumya K. Manna ◽  
Venketesh N. Dubey
Keyword(s):  
Weight Ratio ◽  
Joint Movement ◽  
Sensory Data ◽  
Second Stage ◽  
Actuation Mechanism ◽  
Single Structure ◽  
Three Stages ◽  
Last Stage ◽  
Safety Features ◽  
Intensive Rehabilitation

Abstract Patients suffering from stroke need to undergo a standard and intensive rehabilitation therapy. The rehabilitation training consists of three sequential stages: the first stage is controlled joint movement under external actuator, the second stage deals with supporting the movements by providing assistive force, and the last stage provides variety and difficulty to exercises. Most of the exoskeletons developed so far for rehabilitation are restricted to a particular type of activity. Although a few exoskeletons incorporate different modes of rehabilitation, those are software controlled requiring sensory data acquisition and complex control architecture. To bridge this gap, a portable elbow exoskeleton has been developed for delivering three stages of rehabilitation in a single structure without affecting the range of motion and safety features. Use of electric motor and springs have been arranged in the actuation mechanism to minimize the energy consumption. The developed exoskeleton enhances torque to weight ratio compared to existing models, and all the three modes of rehabilitation have been controlled using a single motor.

scholarly journals Factors Determining the Efficiency of Slovak Public Procurement

2019 ◽  
Vol 12 (1) ◽  
pp. 43-68 ◽  
Author(s):  
Matus Grega ◽  
Marta Orviska ◽  
Juraj Nemec ◽  
Colin Lawson
Keyword(s):  
Public Procurement ◽  
Government Officials ◽  
Face To Face ◽  
Second Stage ◽  
The Core ◽  
Three Stages ◽  
Last Stage ◽  
Main Factors ◽  
The Impact ◽  
Depth Interviews

AbstractMany studies analyse factors (such as corruption, competitiveness, transaction costs), which are influencing public procurement efficiency. The purpose of this paper is to find out, what the main factors are in Slovakia that are influencing public procurement efficiency, and based on our analysis, we will also estimate what is the impact of each factor on the efficiency of public procurement in Slovakia.The research for this paper was executed in three stages. We began with a small number of face-to-face in-depth interviews with specialist procurement advisors to contracting authorities. In the second stage, we created draft questionnaires for contracting authorities and for suppliers, and once we tested questionnaires, it was sent to 13,571 suppliers and to 4,300 contracting authorities. In the last stage, we used various types of analyses to examine identified factors.There is significant agreement between suppliers and contractors that the two main factors causing inefficiencies are excessive bureaucracy and corruption or other ethical shortcomings. It is shown that insufficient competition, and the excessive use of the lowest price criterion for selecting winning bids, add further inefficiencies. Savings are greatest when there are between 6 and 8 bidders. E-auctions generally produce larger savings than more traditional methods, but Slovak procurement procedures are costly, compared to most other EU states.This paper contributes to the understanding of what are the core factors which may influence public procurement efficiency. It also provides valuable information for government officials on how to change public procurement rules in order to achieve higher efficiency.

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