The Robust Linkage Synthesis for Planar Rigid-Body Guidance

2010 ◽  
Author(s):  
Khalid Al-Widyan ◽  
Jorge Angeles
Keyword(s):  
Rigid Body ◽  
Robust Design ◽  
Theoretical Framework ◽  
Planar Motion ◽  
Kinematic Synthesis ◽  
The Subject ◽  
Four Bar Linkage ◽  
Guidance Problem ◽  
Selection Of ◽  
Linkage Synthesis

The kinematic synthesis of planar motion generators in the presence of an incomplete set of finitely separated poses is the subject of this paper. Given that the planar rigid-body guidance problem in the realm of four-bar linkage synthesis can be solved exactly for up to five prescribed poses of the coupler link, any number of poses smaller than five is considered incomplete in this paper. The poses completing the set are determined so as to produce a robust linkage against variations in the unspecified poses. To this end, a theoretical framework for model-based robust design is invoked and a general methodology for robust kinematic synthesis is laid down. Robustness is needed in this context to overcome the presence of uncertainty due to the selection of the unprescribed poses, which many a time are left up to the mechanism designer’s judgment. To validate the concepts and illustrate the application of the methodology proposed here, an example is included.

The Kinematic Synthesis of a Robust RCCC Mechanism for Pick-and-Place Operations

2012 ◽  
Author(s):  
Khalid M. Al-Widyan ◽  
Jorge Angeles
Keyword(s):  
Rigid Body ◽  
Robust Design ◽  
Theoretical Framework ◽  
Synthesis Problem ◽  
Kinematic Synthesis ◽  
General Methodology ◽  
Pick And Place ◽  
Four Bar Linkage ◽  
Pick And Place Operation ◽  
Selection Of

Proposed in this paper is a methodology to synthesize a RCCC four-bar linkage intended for pick-and-place operations. The synthesis problem is set in the context of rigid-body guidance, which can be solved exactly for up to four prescribed poses of the coupler link. As a consequence, for a pick-and-place operation, the selection of the unspecified two intermediate poses is thus left up to the mechanism designer’s judgment. In this paper, we propose a method to determine the two intermediate poses resorting to the concept of robustness. In fact, robustness is needed in this context to overcome the presence of uncertainty due to the selection of the two unspecified poses. To this end, a theoretical framework for model-based robust design is invoked and a general methodology for robust kinematic synthesis is laid down. A numerical example is included to validate the concepts and illustrate the application of the methodology proposed here.

The Synthesis of Spherical Motion Generators in the Presence of an Incomplete Set of Attitudes

2014 ◽  
Vol 6 (3) ◽  
Author(s):  
Khalid Al-Widyan ◽  
Jorge Angeles
Keyword(s):  
Rigid Body ◽  
Engineering Design ◽  
Theoretical Framework ◽  
General Methodology ◽  
Four Bar Linkage ◽  
Robust Engineering Design ◽  
Guidance Problem ◽  
Spherical Motion ◽  
Spherical Rigid Body ◽  
Selection Of

Proposed in this paper is a general methodology applicable to the synthesis of spherical motion generators in the presence of an incomplete set of finitely separated attitudes. The spherical rigid-body guidance problem in the realm of four-bar linkage synthesis can be solved exactly for up to five prescribed attitudes of the coupler link, and hence, any number of attitudes smaller than five is considered incomplete in this paper. The attitudes completing the set are determined to produce a linkage whose performance is robust against variations in the unprescribed attitudes. Robustness is needed in this context to overcome the presence of uncertainty due to the selection of the unspecified attitudes, that many a time are specified implicitly by the designer upon choosing, for example, the location of the fixed joints of the dyads. A theoretical framework for model-based robust engineering design is thus, recalled, and a methodology for the robust synthesis of spherical four-bar linkages is laid down. An example is included here to concretize the concepts and illustrate the application of the proposed methodology.

Introduction

2017 ◽  
Keyword(s):  
United States ◽  
The United States ◽  
Theoretical Framework ◽  
Human Hand ◽  
Theoretical Context ◽  
Critical Questions ◽  
Central Set ◽  
The Status ◽  
The Subject ◽  
Selection Of

The Introduction provides an overview of the central questions and the theoretical framework of the book. Since the early 1990s in Europe and the United States many artists critically re-appropriated religious, motifs, themes and images to produce works that cannot qualify as ‘religious,’ but remains in a dialogue with the visual legacy of mostly the Western, and more specifically the Catholic, version of Christianity. Present-day art does not embed religious images to celebrate them, but in order to pose critical questions concerning central aspects of the rules that regulate the status of images, their public significance, the conditions of their production and authorship, and their connection to an origin or tradition, a context or an author that guarantees their value. The motif of the true image or acheiropoietos (not made by a human hand) is related to central set of features that allow distinguishing between regimes or eras of the image. Its transformations provide a conceptual matrix for understanding of the reconfiguring relationships between art and religion. The introduction provides an overview of the theoretical context, the selection of artworks, bibliography on the subject and the chapters of the book.

scholarly journals Searching for a Path: A Bibliometric study on Innovation and Technological Capabilities

2015 ◽  
Vol 3 (2) ◽  
pp. 54-66 ◽  
Author(s):  
João Heitor De Avila Santos ◽  
Paulo Antonio Zawislak ◽  
Gabriel Borela Franzoni ◽  
Henrique Correa Vieira
Keyword(s):  
Theoretical Framework ◽  
Technological Capability ◽  
Bibliometric Study ◽  
Technological Capabilities ◽  
Innovative Behavior ◽  
Field Of Study ◽  
The Subject ◽  
Scopus Database ◽  
Selection Of

Innovation is recognize as a matter of survival and success to firms and technological capabilities can lead to an innovative behavior by using technological resources and competences. The literature about technological capability and innovation is vast, counting on several approaches and a large number of researchers involved within. Based on this, our aim is to use a bibliometrics approach to map out the authors, institutions, journals and the evolution of the publication as well, to provide the path needed to build a theoretical framework about the theme. We held this research on the Scopus database using a standard search protocol to perform the selection of the sample. Our results indicates an emerging field of study and a large number papers and citations concentrated in few journals. Most cited authors are related to seminal works on the subject and most cited papers are ones from late 90’s and early 2000.

Software for the Kinematic Synthesis of Coupler-Driven Spherical Four-Bar Mechanisms

2007 ◽  
Author(s):  
Eric M. Grimm ◽  
Andrew P. Murray ◽  
Michael L. Turner
Keyword(s):  
Rigid Body ◽  
Kinematic Synthesis ◽  
Prismatic Joint ◽  
Second Stage ◽  
Typical Scheme ◽  
Four Bar Linkage

A spatial analogue of the Stephenson III six-bar mechanism can be formed by the connection of an SPS chain to the coupler of a spherical four-bar linkage. With the prismatic joint actuated, the spherical four-bar is driven via a force applied directly to the coupler. This linkage is termed the coupler-driven spherical four-bar mechanism, and defines an alternative to the typical scheme of actuating the four-bar via a torque applied at the input link. This paper presents software developed to assist in the kinematic synthesis of these mechanisms. In the first stage of the design, a circuit-defect free spherical four-bar is dimensioned with the capacity to guide a rigid body through two orientations. The second stage of the design is to locate the SPS leg such that the four-bar is smoothly drivable between the orientations.

A Robust Solution to the Spherical Rigid-Body Guidance Problem

2003 ◽  
Author(s):  
Khalid Al-Widyan ◽  
Jorge Angeles
Keyword(s):  
Rigid Body ◽  
Robust Solution ◽  
Robust Algorithm ◽  
Guidance Problem ◽  
Spherical Rigid Body ◽  
Unit Vectors ◽  
Linkage Synthesis

In this paper we introduce a robust algorithm to solve the five-attitude spherical Burmester problem associated with exact linkage synthesis. The proposed algorithm solves for the unit vectors determining the four joint centers of the linkage while taking into account all redundant equations available, which enhances the robustness of the algorithm. In order to show the applicability of the proposed algorithm and to validate its robustness, two examples are included.

Planar Linkage Synthesis for Rigid Body Guidance Using Poles and Rotation Angles

2013 ◽  
Author(s):  
Ronald A. Zimmerman
Keyword(s):  
Rigid Body ◽  
Synthesis Method ◽  
Synthesis Methods ◽  
Center Point ◽  
Circle Center ◽  
Previous Solution ◽  
Design Software ◽  
Position Synthesis ◽  
Four Bar Linkage ◽  
Linkage Synthesis

A graphical four bar linkage synthesis method for planar rigid body guidance is presented. This method, capable of synthesis for up to five specified coupler positions, uses the poles and rotation angles, which are constraints, to define guiding links. Faster and simpler than traditional graphical synthesis methods, this method, allows the designer to see and consider most or all the possible solutions within a few seconds before making any free choices. All of the guiding links satisfying five specified coupler positions can be obtained graphically within 30 minutes without plotting any Burmester curves and without any mechanism design software. For four positions, both the circle and center point curves are simultaneously traced by corresponding circle-center point pairs using three poles having a common subscript and the corresponding rotation angles without any additional construction. This method eliminates the iterative construction required in previous methods which were based on free choices rather than constraints. The tedious plotting of Burmester curves graphically using pole quadrilaterals is also eliminated. The simplicity of the method makes four and five position synthesis practical to do graphically. A corresponding analytical solution is presented which provides a simpler formulation than the previous solution method. This new method requires two fewer equations and provides a new way to plot Burmester curves analytically.

Thomas More’s Correspondence in a Spanish Ambiance

Moreana ◽  
2002 ◽  
Vol 39 (Number 149) (1) ◽  
pp. 41-60 ◽  
Author(s):  
Eugenio M. Olivares Merino
Keyword(s):  
The Subject ◽  
Selection Of

The recent reprinting of Álvaro de Silva’s 1998 edition of a selection of More’s letters prompts the author to examine the subject of Spanish translations of More, and of de Silva’s general commentary on More’s correspondence and on his relationship to other humanists. The author reflects on aspects of More’s personality as exposed in his letters and uses what he finds as a corrective to several biographical misconceptions. He points out the strengths and weaknesses of de Silva’s work and compares it with that of other translators, particularly Elizabeth Rogers, and notes the particularly Spanish quality of de Silva’s edition.

Un estudio de caso en el análisis de la espiritualidad en el trabajo

Oikos ◽  
2016 ◽  
Vol 19 (39) ◽  
pp. 29
Author(s):  
Zahira Moreno Freites ◽  
María García Jiménez ◽  
Judith Hernández
Keyword(s):  
Qualitative Analysis ◽  
Work Environment ◽  
Theoretical Framework ◽  
Personal Life ◽  
Theoretical Construct ◽  
Spiritual Beliefs ◽  
High Interest ◽  
Beliefs And Values ◽  
The Subject ◽  
Estudio De Caso

RESUMENEsta investigación examina la espiritualidad y su consideración en el ambiente laboral, específicamente en los trabajadores de la Dirección de Educación Estadal del Municipio Palavecino, Estado Lara, Venezuela. El estudio de tipo descriptivo y cualitativo permitió analizar materiales teóricos relacionados con la espiritualidad en el trabajo, tomando el concepto de espiritualidad de Mitroff y Denton (1999) como marco teórico para esta investigación, además de los aportes de Pérez (2007) y Robles (2011) que exploran el tema y permitieron la elaboración de un constructo teórico para esta investigación. Los resultados evidencian que existe un alto interés por el tema de la espiritualidad tanto en la vida personal como en el trabajo y puede tratarse abiertamente en el ámbito laboral, a pesar de las limitaciones sobre el tema, su principal beneficio es que favorece el equilibrio en todos los aspectos de la vida.Palabras clave: espiritualidad, ambiente laboral, creencias y valores espirituales.An study of case on the analysis of spirituality at the workABSTRACT This research examines spirituality and its consideration in the workplace, specifically on workers of the Directorate of Education of the Municipality Palavecino State Authority, State Lara, Venezuela. The study of descriptive and qualitative analysis allowed theoretical materials related to spirituality at work, taking the concept of spirituality Mitroff and Denton (1999 ) as the theoretical framework for this research, along with the contributions of Perez (2007) and Robles ( 2011) that explore the issue and allowed the development of a theoretical construct for this research. Los results show that there is a high interest in the topic of spirituality both in personal life and at work and can openly addressed in the workplace, despite the limitations on the subject, its main benefit s that it favors the balance in all aspects of life .Keywords: spirituality, work environment, spiritual beliefs and values. Um estudo de caso na análise da espiritualidade no trabalho RESUMO Esta pesquisa analisa a espiritualidade e sua consideração no local de trabalho, especificamente nos trabalhadores do Departamento de Educação Estadual do Município Palavecino, Estado de Lara, Venezuela. O estudo de análise descritiva e qualitativa permitiu investigar materiais teóricos relacionados à espiritualidade no trabalho, tomando o conceito de espiritualidade de Mitroff e Denton (1999) como marco teórico para esta pesquisa, juntamente com as contribuições de Pérez (2007) e Robles ( 2011) que exploram o tema e permitiram o desenvolvimento de uma construção teórica para esta pesquisa. Os resultados mostram que existe um alto interesse pela temática da espiritualidade tanto na vida pessoal como no trabalho e pode-se tratar abertamente no espaço de trabalho, apesar das limitações sobre o assunto, seu principal benefício é que favorece o equilíbrio em todos os aspectos da vida.Palavras-chave: espiritualidade, ambiente de trabalho, crenças e valores espirituais.

Tanks in the Spa Town. The New Book about the Events of the Year 1968 in Czechoslovakia

2019 ◽  
Vol 14 (1-2) ◽  
pp. 278-282
Author(s):  
Kirill A. Popov
Keyword(s):  
Fiftieth Anniversary ◽  
Warsaw Pact ◽  
Scientific Event ◽  
The Social ◽  
Prague Spring ◽  
The Subject ◽  
Scientific Terms ◽  
Selection Of ◽  
Regional Perspective ◽  
The Way

This review is devoted to the monograph by Jan Nedvěd “We do not decline our heads. The events of the year 1968 in Karlovy Vary”. The Karlovy Vary municipal museum coincided its publishing with the fiftieth anniversary of the Prague spring which, considering the way of the presentation, turned the book not only to scientific event but also to the social one. The book describes sociopolitical trends in the region before the year 1968, the development of the reformist movement, the invasion and advance of the armies of the Warsaw Pact countries, and finally the decline of the reformist mood and the beginning of the normalization. Working on his writing, the author deeply studied the materials of the local archive and gathered the unique selection of the photographs depicting the passage of the soviet army through the spa town and the protest actions of its inhabitants. In the meantime, Nedvěd takes undue freedom with scientific terms, and his selection of historiography raises questions. The author bases his research on the Czech papers and scarcely uses the books of Russian origin. He also did not study the subject of the participating of the GDR’s army in the operation Danube, although these troops were concentrated on the borders of Karlovy Vary region as well. Because of this decision, there are no materials from German archives or historiography in the monograph. In general, the work lacks the width of studying its subject, but it definitively accomplishes the task of depicting the Prague spring from the regional perspective.

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